Synthetic mimics of MIR-124

ABSTRACT

Embodiments concern methods and compositions involving miR-124 mimics. In some embodiments, there are double-stranded RNA molecules with modified nucleotides having an active strand with a miR-124 sequence and a complementary passenger strand.

This application claims priority to U.S. provisional patent application61/439,272 filed on Feb. 3, 2011, which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates to the fields of molecular biology andmedicine. More specifically, there are methods and compositionsinvolving RNA molecules with at least the functional properties ofmiR-124, and in some embodiments, enhanced characteristics related tomiR-124 for the treatment of diseases and/or conditions.

II. Background

In 2001, several groups used a cloning method to isolate and identify alarge group of “microRNAs” (miRNAs) from C. elegans, Drosophila, andhumans (Lau et al., 2001; Lee and Ambros, 2001; Lagos-Quintana et al.,2003).

Published human mature microRNA sequences, described in the databasemiRBase 15.0 (Griffths-Jones et al., 2006), range in size from 16-27nucleotides in length and arise from longer precursors. The precursorsform structures that fold back on themselves in self-complementaryregions and are processed by the nuclease Dicer (in animals) or DCL1 (inplants) to generate the short double-stranded mature miRNA. One of themature miRNA strands is incorporated into a complex of proteins andmiRNA called the RNA-induced silencing complex (RISC). The miRNA guidesthe RISC complex to a target mRNA, which is then cleaved ortranslationally silenced, depending on the degree of sequencecomplementarity of the miRNA to its target mRNA. Currently, it isbelieved that perfect or nearly perfect complementarity leads to mRNAdegradation, as is most commonly observed in plants. In contrast,imperfect base pairing, as is primarily found in animals, leads totranslational silencing. However, recent data suggest additionalcomplexity (Bagga et al., 2005; Lim et al., 2005), and mechanisms ofgene silencing by miRNAs remain under intense study.

Studies have shown that changes in the expression levels of numerousmiRNAs are associated with various cancers (reviewed in Calin and Croce,2006; Esquela-Kerscher and Slack, 2006; Wiemer, 2007). miRNAs have alsobeen implicated in regulating cell growth and cell and tissuedifferentiation—cellular processes that associated with the developmentof cancer.

The activity of a variety of miRNAs has been identified and analyzed.Although effective miRNA mimics have been identified previously in U.S.Patent Application Publication 20080050744, which is hereby incorporatedby reference, there is a need for additional miRNA mimics that greatlyimprove one or more properties of the naturally occurring miRNA,particularly as these molecules move from the laboratory to the clinic.

SUMMARY OF THE INVENTION

Therapeutic microRNAs should be stable, active, and specificallyhybridize with the correct mRNA target. Embodiments concern miR-124mimics that have maintained and/or enhanced resistance to nucleasedigestion, hybridization capability with the correct target mRNAs,and/or functionality.

Embodiments concern different RNA molecules containing the sequence of amature miR-124. RNA molecules may be double-stranded and/or blunt-ended,which means the molecule is double-stranded throughout the moleculeand/or blunt-ended on both ends. Moreover, embodiments concern chemicalmodifications of such RNA molecules to yield miR-124 mimics withimproved or enhanced properties. The active strand of a double strandedRNA molecule contains a mature miR-124 sequence. In certain embodiments,the sequence of one strand of a double stranded RNA molecule consists ofthe sequence of a mature miR-124 sequence.

In some embodiments there is an RNA molecule that is double-stranded,meaning the molecule is composed of two polynucleotides or strands thatcan be separated from one another. A double-stranded molecule does notinclude a hairpin molecule, which is one strand or polynucleotide. Insome embodiments, the RNA molecule is blunt-ended on one or both ends.In a double-stranded RNA molecule, one or both strands may be 18, 19,20, 21, 22, 23, 24, or 25 nucleotides in length, or any range derivabletherein. In certain embodiments, a double-stranded, blunt-ended moleculeis 20, 21, or 22 basepairs (bps) in length.

It is contemplated that in some embodiments a double-stranded RNAmolecule contains two strands that are fully complementary to oneanother, which results in a molecule that is necessarily blunt-ended.

In certain embodiments, an RNA molecule has an active strand comprisinga mature human miR-124 sequence (5′-UAAGGCACGCGGUGAAUGCC-3′) (SEQ IDNO:1) (20-mer). In certain embodiments, the mature miR-124 sequence hasthe sequence of SEQ ID NO:1 and an additional U at the 5′ end and anextra A at the 3′ end (5′-UUAAGGCACGCGGUGAAUGCCA-3′) (SEQ ID NO:2)(22-mer). Thus, in certain embodiments, an RNA molecule has an activestrand with the sequence of nucleotides 2 through 21 of SEQ ID NO:2. Inadditional embodiments, an RNA molecule has an active strand with thesequence of nucleotides 2 through 21 of SEQ ID NO:2, but is 21 or 22nucleotides in length because 1) at the 5′ end there is an additionalnucleotide selected from the group consisting of A, C, G, and U and/or2) at the 3′ end there is an additional nucleotide selected from thegroup consisting of A, C, G, U. Thus, an RNA molecule with an activestand having the sequence of SEQ ID NO:2 is specifically contemplated inthe embodiment discussed in the previous sentence. In some embodiments,the active strand has a modified nucleotide at one or more internalpositions.

By convention, sequences discussed herein are set forth 5′ to 3′ unlessother specified. Moreover, a strand containing the sequence of a SEQ IDNO has that sequence from 5′ to 3′ unless otherwise specified.

The term “internal positions” refers to a position that is neither thefirst nor last position in the strand. The term “modified nucleotide”means a nucleotide or nucleoside (if referring to the nucleobase at the5′ position) with an additional moiety or a replacement moiety comparedto an unmodified nucleotide. With active strands containing one or moremodified nucleotides, it is contemplated that there are, there are nofewer than, or there are no more than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12, 13, 14, or 15 modified nucleotides, or any range derivable therein.It is specifically contemplated that in some embodiments, fewer thanevery nucleotide in the active strand is modified, and that fewer thanhalf of the nucleotides in the active strand are modified in certainembodiments. Moreover, in some embodiments, it is specificallycontemplated that an active strand having multiple modified nucleotidesdoes not have every or every other nucleotide in the active strandmodified. The miRNA mimics disclosed herein are sequence- and/orposition-specific.

In some embodiments, the active strand comprises at least two modifiednucleotides. In additional embodiments, the active strand does not havea modified nucleotide in the first two positions at either end. Infurther embodiments, the active strand does not comprise a modifiednucleotide in the first four positions from the 5′ end.

In some embodiments, an active strand may comprise a mature miR-124sequence of SEQ ID NO:1 (5′-UAAGGCACGCGGUGAAUGCC-3′) or comprise thesequence of nucleotides 2 through 21 of SEQ ID NO:2(5′-UUAAGGCACGCGGUGAAUGCCA-3′). SEQ ID NO:2 has the mature miR-124sequence of SEQ ID NO:1 in conjunction with an additional U at the 5′end and an extra A at the 3′ end. In either of these embodiments, theactive strand comprises the same sequence. In additional embodiments, anactive strand has a sequence that comprises or consists of SEQ ID NO:2.In some embodiments, an active strand may have modified nucleotides inwhich the identity of those modified nucleotides is relative to the SEQID NO: being referred to.

In specific embodiments, the modified nucleotides in the active strandare the nucleotides located at positions 5 (G), 6 (G), 7 (C), 8 (A), 11(C), 12 (G), 17 (A), 18 (U), 19 (G), and/or 20 (C) relative to SEQ IDNO:2. This means they are the nucleotides corresponding to thosenucleotides in the recited position in the recited SEQ ID NO. Moreover,these recited nucleotides are situated at positions 4 (G), 5 (G), 6 (C),7 (A), 10 (C), 11 (G), 16 (A), 17 (U), 18 (G), and/or 19 (C),respectively, in SEQ ID NO:1. In other embodiments, an active strand hasa modified nucleotide located at the following positions: 4, 5, 6, 7, 8,10, 11, 12, 16, 17, 18, 19, and/or 20 in the active strand.

An active strand comprising the sequence of nucleotides 2 through 21 ofSEQ ID NO:2 and having a modified nucleotide at position 5 relative toSEQ ID NO:2 means the first G in the sequence of 2-21 of SEQ ID NO:2 ismodified. In other words, unless otherwise specified, modifiednucleotides in the context of a SEQ ID NO are nucleotide-specific. Witha 22-base active strand comprising SEQ ID NO:2 (22 residues in length),the positions of the modified nucleotides relative to SEQ ID NO:2constitute the same recited positions in the 22-base active strandbecause the 22-base active strand has the same sequence as SEQ ID NO:2.Under these circumstances, the modified nucleotides in the active strandare the nucleotides located at positions 5 (G), 6 (G), 7 (C), 8 (A), 11(C), 12 (G), 17 (A), 18 (U), 19 (G), and/or 20 (C) in SEQ ID NO:2.

Thus, in certain embodiments, an RNA molecule has an active strandhaving the sequence of nucleotides 2 through 21 of SEQ ID NO:2. In someembodiments, the active strand has a modified nucleotide at one or moreinternal positions. In additional embodiments, the active strandcomprises at least two modified nucleotides located at positions 5 (G),6 (G), 7 (C), 8 (A), 11 (C), 12 (G), 17 (A), 18 (U), 19 (G), and/or 20(C) relative to SEQ ID NO:2. In further embodiments, there are at least3, 4, 5, 6, 7, 8, 9, or 10 modified nucleotides (or any range derivabletherein) located at positions 5 (G), 6 (G), 7 (C), 8 (A), 11 (C), 12(G), 17 (A), 18 (U), 19 (G), and/or 20 (C) relative to SEQ ID NO:2.

When the particular nucleotide base is designated (as an “A,” “C,” “G,”or “U”) and is described as “relative” to a position in a sequence (suchas a SEQ ID NO:2), this means that the modification of that particulardesignated nucleotide is contemplated in the strand even if its positionchanges by 1 or 2 positions (±1 or ±2 positions) (because of a deletionor insertion with respect to the reference sequence). In otherembodiments, a modified nucleotide is described with respect to positionin the strand and not as relative to a particular SEQ ID NO:2; in thatcase, position refers to the position in the strand, where the 5′ end ofthe strand begins with position 1 and continues through 2, 3, 4, etc.until the nucleotide position at the 3′ end is reached.

In certain embodiments, the active strand comprises no more than sixmodified nucleotides.

In other embodiments, the active strand has a modified nucleotide at oneor more of the following positions 1 (U), 2 (U), 3 (A), 4 (A), 9 (C), 10(G), 11 (C), 12 (G), 13 (G), 14 (U), 15 (G), 16 (A), 21 (C), and/or 22(A) relative to SEQ ID NO:2. In other embodiments, the active strand hasa modified nucleotide at position 1, 2, 3, 4, 8, 9, 10, 12, 13, 14, 15,16, 20, 21, and/or 22 in the active strand. These may be instead of orin addition to modifications at other positions discussed herein.

In some embodiments, the active strand comprises a modified nucleotideat positions 7 (C) and 8 (A) relative to SEQ ID NO:2. In additionalembodiments, the active strand further comprises a modified nucleotideat positions 17 (A) and 18 (U) relative to SEQ ID NO:2 or a modifiednucleotide at positions 9 (C), 10 (G), 11 (C), and 12 (G) relative toSEQ ID NO:2. In other embodiments, the active strand has a modifiednucleotide at position 8, 9, 10, 12, 16, 17, and/or 18 in the activestrand. These may be instead of or in addition to modifications at otherpositions discussed herein.

In some embodiments, RNA molecules that are double-stranded contain bothan active strand comprising all of part of the sequence of a maturemiRNA and a passenger strand fully or partially complementary to theactive strand. In some embodiments, the passenger strand is, is atleast, or is at most 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92,93, 94, 95, 96, 97, 98, 99, or 100% complementary, or any rangederivable therein, to the active strand. In certain embodiments, theactive and passenger strands are fully complementary to each other.

With passenger strands containing one or more modified nucleotides, itis contemplated that there are, there are no fewer than, or there are nomore than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 modifiednucleotides, or any range derivable therein. It is specificallycontemplated that in some embodiments, fewer than every nucleotide inthe passenger strand is modified, and that fewer than half of thenucleotides in the passenger strand are modified in certain embodiments.Moreover, in some embodiments, it is specifically contemplated that apassenger strand having multiple modified nucleotides does not haveevery other nucleotide in the passenger strand is modified.

In such embodiments, the passenger stand comprises a nucleotidemodification at the 5′ end, which may be referred to as a 5′ terminalmodification. Such a terminal modification may be with respect to thenucleotide (or nucleoside if it lacks a phosphate group) at the 5′ end.This terminal modification is specifically contemplated in someembodiments to be a modification that is not a modification of a sugarmolecule. It is specifically contemplated that this modification may beone of the following: NH₂, biotin, an amine group, a lower alkylaminegroup, NHCOCH₃, an acetyl group, 2′O-Me, DMTO, fluorescein, a thiol,acridine, Spacer 18 (PEG) amidite (DMT-Hexa(ethylene glycol)), or anyother group with this type of functionality. In specific embodiments,the 5′ terminal modification on the passenger strand is a C6 aminelinker. In further embodiments, the nucleotide at the 5′ end of thepassenger strand may have both a non-sugar modification and a sugarmodification.

In some embodiments, a passenger strand contains at least one modifiednucleotide in the first six nucleotides and/or the last six nucleotideswith respect to the 5′ end of the passenger strand. In otherembodiments, the passenger strand has, has at least, or has at most 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or more modifiednucleotides, or any range derivable therein.

In certain embodiments, the passenger strand comprises a modifiednucleotide located at positions 1 (U), 2 (G), 3 (G), 4 (C), 5 (A), 6(U), 13 (C), 14 (G), 15 (U), 16 (G), 17 (C), 18 (C), 19 (U), 20 (U), 21(A), and/or 22 (A) relative to SEQ ID NO:4(5′-UGGCAUUCACCGCGUGCCUUAA-3′). SEQ ID NO:4 contains a sequence that isfully complementary to SEQ ID NO:2. SEQ ID NO:4 has an extra U at the 5′end and an extra A at the 3′ end compared to the complement of the humanmiR-124 sequence in the miRBase 16.0 database (Griffths-Jones et al.,2006) (the mature miR-124 sequence is SEQ ID NO:1, and its complement isSEQ ID NO:3). In some embodiments, a passenger strand consists of orcomprises SEQ ID NO:3, but does not consist of or comprise SEQ ID NO:4.The modified nucleotides relative to SEQ ID NO:4 (set forth above)correspond in SEQ ID NO:3 (5′-GGCAUUCACCGCGUGCCUUA-3′) to those atpositions 1 (G), 2 (G), 3 (C), 4 (A), 5 (U), 12 (C), 13 (G), 14 (U), 15(G), 16 (C), 17 (C), 18 (U), 19 (U), and/or 20 (A).

In some embodiments, a passenger strand comprises a modified nucleotideas positions 1 (U) and 22 (A) relative to SEQ ID NO:4. In furtherembodiments, the passenger strand comprises a modified nucleotide aspositions 2 (G) and 21 (A) relative to SEQ ID NO:4, which may be inaddition to or instead of modifications at positions 1 (U) and 22 (A).In certain embodiments, the passenger strand comprises a modifiednucleotide at positions 1 (U), 2 (G), 3 (G), 20 (U), 21 (A), and 22 (A)relative to SEQ ID NO:4. It is further contemplated that the passengerstrand may comprise or further comprise a modified nucleotide atposition 4 (C) relative to SEQ ID NO:4. In other embodiments, thepassenger strand further comprises a modified nucleotide at positions 5(A) and 6 (U) relative to SEQ ID NO:4 in addition to modifiednucleotides at positions i) 1 (U) and 22 (A) and/or ii) 4 (C) relativeto SEQ ID NO:4.

In certain embodiments, the passenger strand does not have a modifiednucleotide located at positions 7 (U), 8 (C), 9 (A), 10 (C), 11 (C), or12 (G) relative to SEQ ID NO:4, while in other embodiments, one or morepositions relative to SEQ ID NO:4 are contemplated.

Combinations of a particular active strand and a particular passengerstrand are contemplated. It is contemplated that any active stranddescribed herein may be combined with any passenger strand describedherein to form a double-stranded RNA molecule. In some embodiments,there is a passenger strand comprising modified nucleotides at positions2 (G) and 21 (A) relative to SEQ ID NO:4 and an active strand comprisingmodified nucleotides at positions 7 (C) and 8 (A) relative to SEQ IDNO:2. In further embodiments, the passenger strand further comprisesmodified nucleotides at positions 1 (U) and 22 (A) in SEQ ID NO:4, whichmay be instead of or in addition to modifications at positions 3(G) and20 (U) relative to SEQ ID NO:4. In additional embodiments, the activestrand may further comprise modified nucleotides at positions 17 (A) and18 (U) relative to SEQ ID NO:2.

In some embodiments, there is a double-stranded, blunt-ended RNAmolecule with 1) an active strand with the sequence of SEQ ID NO:2 andmodified nucleotides at positions 7 (C) and 8 (A), and optionally alsoat positions 9 (C), 10 (G), 11 (C), and 12 (G) and or positions 17 (A)and 18 (U) relative to SEQ ID NO:2; and 2) a passenger strand with a 5′terminal modification and nucleotide modifications in the first and lastthree nucleotides, and optionally nucleotide modifications also atposition 4 (C), 5 (A), and/or 6 (U) relative to SEQ ID NO:4. In certainembodiments, this combination of active and passenger strands has a 5′terminal modification of the passenger strand in which the terminalmodification is an alkyl amine such as a C6 amine linker, and thenucleotide modifications are on the sugar at the 2′ position. Inspecific embodiments, the sugar modification is a 2′OMe.

In some embodiments, there is a double-stranded, blunt-ended RNAmolecule of 20-22 basepairs in length comprising: a) an active strandcomprising i) the sequence of nucleotides 2 through 21 of SEQ ID NO:2and ii) a modified nucleotide at one or more internal positions, whereinthe strand does not have a modified nucleotide at its 5′ end and thereare no more than 10 modified nucleotides; and, b) a separate passengerstrand that is fully complementary to the active strand and comprises a5′ end nucleotide modification and at least one more modifiednucleotide, wherein the nucleotides located at positions 7-19 relativeto SEQ ID NO:2 are not modified. In specific embodiments, the activestrand comprises the sequence of SEQ ID NO:2.

In further embodiments, there is a double-stranded RNA molecule of 20-22basepairs in length, wherein the RNA molecule is blunt-ended at bothends, comprising an active strand having the sequence of nucleotides 2through 21 of SEQ ID NO:2 and a separate and fully complementarypassenger strand with a modified nucleotide at the 5′ end, wherein theactive strand comprises at least one modified internal nucleotide andwherein the double-stranded RNA molecule is more stable in the presenceof a nuclease compared to a double-stranded, blunt-ended RNA moleculelacking any modification of an internal nucleotide.

In some embodiments, the RNA molecule has nucleotides that are modifiedwith a sugar modification. In specific embodiments, the sugarmodification is 2′-OMe.

Specific embodiments include pharmaceutical compositions containing oneor more different RNA molecules capable of acting as miRNA mimics; thedifference may relate to sequence and/or type or position ofmodification. In certain embodiments, the RNA molecules are comprised ina lipid formulation. In other embodiments, RNA molecules may beformulated with a liposome, polymer-based nanoparticle, cholesterolconjugate, cyclodextran complex, polyethylenimine polymer and/or aprotein complex.

Methods for providing miR-124 activity to a cell are also set forth inembodiments. In some embodiments, there are methods for providingmiR-124 activity to a cell comprising administering to the cell aneffective amount of an RNA molecule having miR-124 activity. In someembodiments, the cell is a cancer cell. Such RNA molecules are discussedthroughout this disclosure.

Other methods include a method for decreasing cell proliferationcomprising administering to the cell an effective amount of a miR-124RNA molecule, such as the double-stranded RNA molecules discussedherein. Additional embodiments include methods for inducing apoptosis ina cell comprising administering to the cell an effective amount of theRNA molecules. Other embodiments concern methods for treating cancer ina patient comprising administering to the patient a pharmaceuticalcomposition comprising one or more of the RNA molecules that have miRNAfunction. Further embodiments concern methods of inhibiting progressionthrough cell cycle by administering an effective amount of the one ormore miR-124 mimics discussed herein. In some embodiments, methodsfurther comprise administering to the patient an additional cancertherapy. In some embodiments, a patient has been tested for and/ordiagnosed with cancer.

Other embodiments concern the use of RNA molecules for treating cancercells, or their use in decreasing cell proliferation, inducing apoptosisor providing miR-124 function to a cell. It is specifically contemplatedfor use with human cells and human patients.

The compositions and methods for their use can “comprise,” “consistessentially of,” or “consist of” any of the molecules or steps disclosedthroughout the specification. With respect to the transitional phase“consisting essentially of,” and in one non-limiting aspect, a basic andnovel characteristic of the compositions and methods disclosed in thisspecification includes the miRNA mimic activity.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.”

It is contemplated that any embodiment discussed herein can beimplemented with respect to any method or composition of the invention,and vice versa. Furthermore, compositions and kits of the invention canbe used to achieve methods of the invention.

Throughout this application, the term “about” is used to indicate that avalue includes the standard deviation of error for the device or methodbeing employed to determine the value.

The use of the term “or” in the claims is used to mean “and/or” unlessexplicitly indicated to refer to alternatives only or the alternativesare mutually exclusive, although the disclosure supports a definitionthat refers to only alternatives and “and/or.” It is also contemplatedthat anything listed using the term “or” may also be specificallyexcluded.

Other objects, features and advantages of the present invention willbecome apparent from the following detailed description. It should beunderstood, however, that the detailed description and the specificexamples, while indicating specific embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments are directed to compositions and methods relating to miRNAs,as well as use of miRNA mimics. Methods include preparing such mimicsand using such mimics to provide miRNA activity or function to a cell.In certain embodiments, miRNA mimics are used for therapeutic,prognostic, and diagnostic applications, particularly those methods andcompositions related to therapeutic applications for conditions ordiseases in which miRNA activity or function is involved.

I. Nucleic Acids

Nucleic acids include the sequences or segments of sequence that areidentical or complementary sequences to mature microRNA (“miRNA” or“miR”) molecules. Mature miRNA molecules are generally 21 to 22nucleotides in length, though lengths of 16 and up to 27 nucleotideshave been reported. The miRNAs are each processed from a longerprecursor RNA molecule (“precursor miRNA”). Precursor miRNAs aretranscribed from non-protein-encoding genes. The precursor miRNAs havetwo regions of complementarity that enable them to form a stem-loop- orfold-back-like structure, which is cleaved in animals by a ribonucleaseIII-like nuclease enzyme called Dicer. The processed miRNA is typicallya portion of the stem.

The processed miRNA (also referred to as “mature miRNA”) becomes part ofa large complex to down-regulate a particular target gene. Examples ofanimal miRNAs include those that imperfectly basepair with the target,which halts translation (Olsen et al., 1999; Seggerson et al., 2002).siRNA molecules also are processed by Dicer, but from a long,double-stranded RNA molecule. siRNAs are not naturally found in animalcells, but they can direct the sequence-specific cleavage of an mRNAtarget through an RNA-induced silencing complex (RISC) (Denli et al.,2003).

A. miR-124

It was previously demonstrated that hsa-miR-124 is involved with theregulation of numerous cell activities that represent interventionpoints for cancer therapy and for therapy of other diseases anddisorders (U.S. patent application Ser. No. 11/141,707 filed May 31,2005 and Ser. No. 11/273,640 filed Nov. 14, 2005, each of which isincorporated herein by reference in its entirety). For example, cellproliferation, cell division, and cell survival are frequently alteredin human cancers. Transfection of human lung carcinoma cells (A549) andhuman cervical cancer cells (HeLa) with synthetic hsa-miR-124 reducedviable cell numbers. In addition, the inventors showed that miR-124significantly increased the capacity of two therapeutic compounds(TRAIL, an apoptosis pathway activator in cancer cells, and etoposide, atopoisomerase II inhibitor that activates the apoptosis pathway incancer cells and normal cells) to induce cell death in A549 or HeLacells. Overexpression of synthetic miR-124 in various cell linesdecreased cell proliferation. In those studies, the inventors observedreduced proliferation of human breast cancer cells (BT549), normal humanbreast epithelial cells (MCF12A), human cervical cancer cells (HeLa),human prostate carcinoma cells (22RV1), human basal cell carcinoma cells(TE 354.T), normal human skin cells (TE 353.5 k), and human lungcarcinoma cells (A549, CRL-5826, HTB-57). Overexpression of miR-124 inHeLa cells significantly reduced the number of cells in the G2/M phaseof the cell cycle when compared to cells transfected with a negativecontrol miRNA. The inventors previously demonstrated that hsa-miR-124regulates the expression of many genes that function in intracellularsignal transduction in response to mitotic or apoptotic stimuli (U.S.patent application Ser. No. 12/325,971 filed Dec. 1, 2008, which isincorporated herein by reference in its entirety). Also, others haverecently observed that epigenetic silencing of miR-124 in cancers cellsmodulates activity of the oncogene, CDK6 and the tumor suppressor gene,Rb (Lujambio et al., 2007).

Hsa-miR-124 affects intracellular signaling at various levels andcontrols the expression of secretory proteins, transmembrane growthfactor receptors, and cytoplasmic signaling molecules. Secretoryproteins include fibroblast growth factor 2 (FGF2), insulin growthfactor binding protein 1 and 3 (IGFBP1, IGFBP3), transforming growthfactor beta-2 (TGFB2), and the inflammatory chemokine interleukin 8(U.S. patent application Ser. No. 12/325,971 filed Dec. 1, 2008). FGF-2is a secretory protein with potent mitogenic and angiogenic activitythat transmits its signal into cells via transmembrane receptors (FGFRs)composed of 2-3 extracellular immunoglobulin-like domains and anintracellular tyrosine kinase domain (Chandler et al., 1999). FGF-2mRNAs levels are increased in renal, oral and non-small cell lung cancercells (Chandler et al., 1999). Similarly, IL-8 is frequently upregulatedin various cancers and correlates with tumor vascularization, metastasisand poor prognosis (Rosenkilde and Schwartz, 2004; Sparmann andBar-Sagi, 2004). TGFB2 is the corresponding ligand to TGF-.beta.receptors (TGFBR), a class of receptors that may function as tumorsuppressors (Massague et al., 2000).

Membrane-associated proteins regulated by hsa-miR-124 areplatelet-derived growth factor receptor-like (PDGFRL; also referred toas PDGF receptor beta-like tumor suppressor, PRLTS) and the Rasassociation domain family protein 2 (RASSF2). (U.S. patent applicationSer. No. 12/325,971 filed Dec. 1, 2008). RASSF2 is a tumor suppressorcandidate that is frequently downregulated in lung tumor cell lines (Voset al., 2003). RASSF2 interacts with K-Ras and promotes cell cyclearrest and apoptosis. PDGFRL also functions as a tumor suppressor thatshows loss of function in a broad variety of cancers either by loss ofheterozygosity (LOH) or mis-sense and frame-shift mutation (Fujiwara etal., 1995; Komiya et al., 1997). Since treatment of cancer cells withhsa-miR-124 leads to reduced expression levels of FGF2, IL8 and IGFBPs,and to increased expression levels of TGFB2, RASSF2 and PDGFRL,hsa-miR-124 is likely to induce a therapeutic response in cancerpatients that show aberrant expression or function of thesegrowth-stimulatory or inhibitory proteins (U.S. patent application Ser.No. 12/325,971 filed Dec. 1, 2008).

Intracellular signaling molecules regulated by hsa-miR-124 includeIkappaB kinase alpha (IKKalpha, CHUK), c-Src (SRC), the catalyticsubunit of class IA phosphoinositide 3-kinases p110.alpha. (PIK3CA) andphospholipase C beta-1 (PLCB1). PLC beta-1 catalyzes the generation ofinositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) fromphosphatidylinositol-bis-phosphate (PIP2), regulating proliferativesignals and checkpoints of the cell cycle (Lo Vasco et al., 2004). (U.S.patent application Ser. No. 12/325,971 filed Dec. 1, 2008). IKKalpha isa positive regulator of the intracellular signaling cascade andfunctions to activate the transcription factor nuclear factor kappa B(NFkappaB) (Karin et al., 2002). NFkappaB is constitutively activated inseveral cancer types and promotes anti-apoptotic and survival pathways.The proto-oncoprotein c-Src is the human homolog of avian v-Src that hasbeen isolated as the tumorigenic component of Rous Sarcoma virus (RSV)(Rous, 1911; Stehelin et al., 1976; Yeatman, 2004). c-Src is amembrane-associated tyrosine kinase that is activated in response tointracellular signaling or indirectly to extracellular stimuli bybinding to activated receptor tyrosine kinases, including EGFR, ERBB2,PDGFR and FGFR. Src is a crucial molecule in a complex network ofinteracting proteins, regulating cell adhesion, motility, invasion andproliferation. c-Src is frequently overexpressed or hyperactivated innumerous cancer types (Yeatman, 2004). The gene product of PIK3CAactivates the Akt signaling pathway in response to most upstreamreceptor tyrosine kinases (Vanhaesebroeck et al., 1997). PIK3CAfrequently acquires a gain of function in the vast majority of humancancers, either by amplification or overexpression, such as in ovarianand cervical cancers, or by activating somatic mutations (Bader andVogt, 2004; Bader et al., 2005). PIK3CA has become a novel drug targetin the pharmaceutical industry and is also a predicted target ofhsa-miR-124. Based on the inventors previous data (U.S. patentapplication Ser. No. 12/325,971 filed Dec. 1, 2008, which is herebyincorporated by reference), hsa-miR-124 negatively regulates theseproteins and therefore is likely to function as a tumor-suppressormiRNA.

Another class of genes and their corresponding proteins that areregulated by hsa-miR-124, functions in the progression of the cell cycle(U.S. patent application Ser. No. 12/325,971 filed Dec. 1, 2008). Someof these proteins are critical in the transition through G1 and Sphases, such as cyclins A2 and E2 (CCNA2, CCNE2), cyclin dependentkinases 2, 4 and 6 (CDK2, CDK4, CDK6) and cell division cycle 6 (CDC6).Others are required for progressing through the G2/M spindle checkpointand proper segregation of sister chromatids during mitosis to maintainchromosomal stability. These include aurora kinases A and B (AURKA,a.k.a. STK6; AURKB, a.k.a. STK12), breast cancer 1 and 2 (BRCA1; BRCA2),budding uninhibited by benzimidazoles 1 (BUB1), budding uninhibited bybenzimidazoles 1 beta (BUB1B), polo-like kinase 1 (PLK1), cyclindependent kinase 1 (CDK1, a.k.a. CDC2), cyclins B1 and B2 (CCNB1,CCNB2), and cell division cycle 20 and 23 (CDC20, CDC23, a.k.a. anaphasepromoting complex subunit 8). Most of these transcripts are regulated ina manner that suggests that hsa-miR-124 blocks cell cycle progression.

Other molecules regulated by hsa-miR-124 that indirectly control cellcycle progression are SKP2, MDM2 and AKAP12 (U.S. patent applicationSer. No. 12/325,971 filed Dec. 1, 2008). AKAP12, also referred to asgravin or SSeCKS (Src suppressed C kinase substrate), functions as akinase scaffold protein that tethers the enzyme-substrate interaction(Nauert et al., 1997). Expression of AKAP12 interferes with oncogeniccell transformation induced by the Src or Jun oncoproteins in vitro andis lost or reduced in numerous cancers, such as leukemia and carcinomasof the rectum, lung and stomach (Lin and Gelman, 1997; Cohen et al.,2001; Xia et al., 2001; Wikman et al., 2002; Boultwood et al., 2004;Choi et al., 2004; Mori et al., 2006). An apparent anti-oncogenicactivity of AKAP12 in prostate and gastric cancers marks this protein asa putative tumor suppressor (Xia et al., 2001; Choi et al., 2004). Skp2is a component of the multi-subunit E3 ubiquitin ligase complex thatear-marks proteins for proteasomal degradation. A well characterizedtarget is the CDK inhibitor p27 which offers an explanation for the cellcycle promoting activity of Skp2 (Carrano et al., 1999). Skp2 isinherently oncogenic and shows elevated levels in various cancer types(Gstaiger et al., 2001; Kamata et al., 2005; Saigusa et al., 2005;Einama et al., 2006).

Hsa-miR-124 also governs the expression of FAS, Bim (BCL2L11) and MCL1,all of which are functionally linked to the apoptotic pathway (U.S.patent application Ser. No. 12/325,971 filed Dec. 1, 2008).

miR-124 has been shown to have the following activities when provided toa cell: reduce cell viability, inhibit cell proliferation, decrease cellproliferation, and inhibit progression through cell cycle. Theseactivities have been shown in diseased cells, such as cancer cells.

B. Oligomeric Compounds

Embodiments concern miRNA mimics, which contain molecules capable ofmimicking the activity of an RNA molecule. An RNA molecule contains anucleoside, which is a base-sugar combination. The base portion of thenucleoside is typically a heterocyclic base moiety. The two most commonclasses of such heterocyclic bases are purines and pyrimidines.Nucleotides are nucleosides that further include a phosphate groupcovalently linked to the sugar portion of the nucleoside. For thosenucleosides that include a pentofuranosyl sugar, the phosphate group canbe linked to the 2′, 3′ or 5′ hydroxyl moiety of the sugar. It iscontemplated that an RNA strand will be composed of nucleotides(ribonucleotides) and that the 5′ end may be a nucleotide or anucleoside. In other words, there may be a phosphate group linked to thesugar portion of the nucleoside or there may be only a hydroxyl groupinstead of the phosphate group. As discussed herein, in someembodiments, there is a modification of a terminal nucleoside ornucleotide in which a chemical moiety or group is attached to the sugarthrough what is, or was formerly, a hydroxyl or phosphate group.

In forming oligonucleotides, the phosphate groups covalently linkadjacent nucleosides to one another to form a linear polymeric compound.The respective ends of this linear polymeric structure can be joined toform a circular structure by hybridization or by formation of a covalentbond. In addition, linear compounds may have internal nucleobasecomplementarity and may therefore fold in a manner as to produce a fullyor partially double-stranded structure. Within the oligonucleotidestructure, the phosphate groups are commonly referred to as forming theinternucleoside linkages of the oligonucleotide. The normalinternucleoside linkage of RNA and DNA is a 3′ to 5′ phosphodiesterlinkage.

In some embodiments, there is an RNA, RNA molecule, or RNA analog havinga length of between 17 and 130 residues. Embodiments concern syntheticmiRNA molecules that are, are at least, or are at most 15, 16, 17, 18,19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,37, 38, 39, or 40 or more residues in length, including any integer orany range derivable therein. Each strand or RNA molecule in adouble-stranded RNA molecule may be such lengths as recited above. Insome embodiments, an RNA molecule has a blunt end on one or both ends.In certain embodiments, the RNA molecule has a blunt end on the sidehaving the 5′ end of the active strand. In other embodiments, the RNAmolecule has a blunt end on the side having the 5′ end of the passengerstrand.

RNA molecules described herein may have one or two strands. In moleculeswith two strands, the two strands may be hybridized to one another, butthey are not connected to one another by an internucleoside linkage.

In certain embodiments, such RNA molecules that comprise or consist ofSEQ ID NO:1 or SEQ ID NO:2 (or that consists of a sequence that has atleast 90% identity with one of the recited SEQ ID NOs) have a modifiednucleotide or nucleoside located at position 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and/or 21 in the activestrand (position 1 is the 5′ end). In further embodiments, a modifiednucleotide or nucleoside is located at position 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and/or 21 in a passengerstrand (position 1 is the 5′ end) that comprises or consists of SEQ IDNO:3 or SEQ ID NO:4 (or that consists of a sequence that has at least90% identity with one of the recited SEQ ID NOs). The designation of themodified nucleotide is position-specific, as opposed tonucleotide-specific. Accordingly, an embodiment in whichnucleotide-specific modifications are discussed, for example, “apassenger strand comprising modified nucleotides at positions 2 (G) and21 (A) relative to SEQ ID NO:4,” may be implemented in other embodimentswith respect to position; consequently, in further embodiments, an RNAmolecule may comprise, for example, a passenger strand comprising amodified nucleotide at positions 2 and 21.

In some embodiments, the miRNA mimic or RNA molecule is not blunt-endedon both sides. It is contemplated that there may be a 1, 2, 3, 4, 5, or6 base overhang on either the 3′ or 5′ end of the passenger or activestrands of a double-stranded RNA mimic or molecule.

In some embodiments, the passenger strand and the active strand are notfully complementary. It is contemplated that there may be 1, 2, 3, 4, 5,6 or more nucleotides between the two strands that are notcomplementary. In some embodiments, these nucleotides are within thefirst 10 nucleotides of the 5′ end of the passenger strand.

It is contemplated that RNA mimics have RNA bases, which may or may notbe modified. As such, RNA mimics are RNA or RNA molecules. Moreover, itis understood that a nucleic acid, including RNA, may have more thanone-strand. As discussed herein, in some embodiments a miRNA mimic orRNA molecule is double-stranded. Unless otherwise specified, adouble-stranded RNA molecule or miRNA mimic will be understood to havetwo strands that can be separated from each other and that are notsimply connected to one another by a hairpin linker. A hairpin moleculehas one strand that is capable of intramolecular hybridization. In someembodiments, the miRNA mimic is a hairpin molecule. In others, the miRNAmimic is a double-stranded RNA molecule.

In certain embodiments, therapeutic double-stranded nucleic acids have afirst active strand with (a) a “miRNA region” whose sequence from 5′ to3′ is identical to all or a segment of a mature miRNA sequence, and asecond passenger strand having (b) a “complementary region” whosesequence from 5′ to 3′ is between 60% and 100% complementary to themiRNA sequence. In certain embodiments, these synthetic miRNA are alsoisolated, as defined below, or purified. The term “miRNA region” refersto a region on the synthetic miRNA that is at least 75, 80, 85, 90, 95,or 100% identical, including all integers there between, to the entiresequence of a mature, naturally occurring miRNA sequence. In certainembodiments, the miRNA region is or is at least 90, 91, 92, 93, 94, 95,96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, 99.9 or100% identical to the sequence of a naturally-occurring miRNA, such asthe human miRNA sequence. Alternatively, the miRNA region can comprise18, 19, 20, 21, 22, 23, 24 or more nucleotide positions in common with anaturally-occurring miRNA as compared by sequence alignment algorithmsand methods well known in the art.

The term “complementary region” refers to a region of a synthetic miRNAthat is or is at least 60% complementary to the mature, naturallyoccurring miRNA sequence that the miRNA region is identical to. Thecomplementary region is or is at least 60, 61, 62, 63, 64, 65, 66, 67,68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85,86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.1, 99.2,99.3, 99.4, 99.5, 99.6, 99.7, 99.8, 99.9 or 100% complementary, or anyrange derivable therein. With single polynucleotide sequences, there maybe a hairpin loop structure as a result of chemical bonding between themiRNA region and the complementary region. In other embodiments, thecomplementary region is on a different nucleic acid strand than themiRNA region, in which case the complementary region is on the passengerstrand and the miRNA region is on the active strand.

The term “oligonucleotide” is understood in the art to refer to anoligomer or polymer of ribonucleic acid (RNA) or deoxyribonucleic acid(DNA), typically one that is no more than 100 bases or base pairs inlength. It is contemplated that an oligonucleotide may have a nucleosideat the 5′ end. This term includes oligonucleotides composed of naturallyoccurring nucleobases, sugars and covalent internucleoside linkages. Theterm “oligonucleotide analog” refers to oligonucleotides that have oneor more non-naturally occurring portions which function in a similarmanner to oligonucleotides. Such non-naturally occurringoligonucleotides may have desirable properties compared to the naturallyoccurring oligonucleotides such as, for example, those disclosed herein,including, but not limited to, increased physiological activity,increased stability in the presence of a nuclease(s), and/or increasedpharmacokinetic properties.

The term “oligonucleoside” refers to nucleosides that are chemicallyconnected via internucleoside linkages that do not have phosphorusatoms. Internucleoside linkages include short chain alkyl, cycloalkyl,mixed heteroatom alkyl, mixed heteroatom cycloalkyl, one or more shortchain heteroatomic and one or more short chain heterocyclic. Theseinternucleoside linkages include, but are not limited to, siloxane,sulfide, sulfoxide, sulfone, acetyl, formacetyl, thioformacetyl,methylene formacetyl, thioformacetyl, alkeneyl, sulfamate;methyleneimino, methylenehydrazino, sulfonate, sulfonamide, amide andothers having mixed N, O, S and CH₂ component parts. In addition to themodifications described above, the nucleosides of the oligomericcompounds of the invention can have a variety of other modifications.Additional nucleosides amenable to embodiments having modified basemoieties and or modified sugar moieties are disclosed in U.S. Pat. No.6,383,808 and PCT application PCT/US89/02323, both of which are herebyincorporated by reference.

Altered base moieties or altered sugar moieties also include othermodifications consistent with the purpose of an miRNA mimic. Sucholigomeric compounds are best described as being structurallydistinguishable from, yet functionally interchangeable with, naturallyoccurring or synthetic unmodified oligonucleotides. All such oligomericcompounds are comprehended by this invention so long as they functioneffectively to mimic the structure or function of a desired RNA or DNAoligonucleotide strand.

In some embodiments, RNA mimics include a base modification orsubstitution. The natural or unmodified bases in RNA are adenine (A) andguanine (G), and the pyrimidine bases cytosine (C) and uracil (U) (DNAhas thymine (T)). In contrast, modified bases, also referred to asheterocyclic base moieties, include other synthetic and naturalnucleobases such as 5-methylcytosine (5-me-C), 5-hydroxymethyl cytosine,xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkylderivatives of adenine and guanine, 2-propyl and other alkyl derivativesof adenine and guanine, 2-thiouracil, 2-thiothymine and 2-thiocytosine,5-halouracil and cytosine, 5-propynyl uracil and cytosine and otheralkynyl derivatives of pyrimidine bases, 6-azo uracil, cytosine andthymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino,8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines andguanines, 5-halo (including 5-bromo, 5-trifluoromethyl and other5-substituted uracils and cytosines), 7-methylguanine and7-methyladenine, 2-F-adenine, 2-amino-adenine, 8-azaguanine and8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine and3-deazaadenine.

One or more base or sugar modifications may be used to induce a 3′-endosugar conformation. A nucleoside can incorporate synthetic modificationsof the heterocyclic base, the sugar moiety or both to induce a desired3′-endo sugar conformation. These modified nucleosides are used to mimicRNA-like nucleosides so that particular properties of an oligomericcompound can be enhanced while maintaining the desired 3′-endoconformational geometry (see Scheme 1 of U.S. Patent ApplicationPublication 2005/0261218, which is hereby incorporated by reference).

In some embodiments, an RNA mimic has a modification particularly of the5′ terminal residue of specifically the strand of an RNA mimic havingthe sequence that is complementary to the mature miRNA. This strand isreferred to as the “passenger” strand herein. Without being bound totheory, it appears that the presence of a stable moiety other than aphosphate or hydroxyl at the 5′ end of the complementary strand impairsor eliminates uptake of the passenger strand by the miRNA pathwaycomplex and subsequently favors uptake of the active strand by the miRNAprotein complex. 5′ modifications include, but are not limited to, NH₂,biotin, an amine group, a lower alkylamine group, a lower alkyl group,NHCOCH₃, an acetyl group, 2′ oxygen-methyl (2′O-Me), DMTO, fluorescein,a thiol, or acridine or any other group with this type of functionality.In other embodiments, there is a Spacer 18 (PEG) amidite(DMT-Hexa(ethylene glycol)). In other embodiments, there is analkylamine or alkyl group of 40 carbons or fewer. In embodimentsinvolving a “lower” alkylamine or alkyl group, “lower” will beunderstood to refer to a molecule with 20 or fewer carbons.

In specific embodiments, there is a C4-C12 amine linker on the 5′ end ofthe passenger strand. In specific embodiments, there is a C6 amine onthe terminal phosphate of the first nucleotide of the passenger strand:

In specific embodiments, there is a C12 amine linker on the 5′ end ofthe passenger strand. In other embodiments, there is a C8 amine linkeron the terminal phosphate of the first nucleotide of the passengerstrand.

In different miRNA mimics discussed herein, these RNA molecules can havenucleotides with sugar portions that correspond to naturally occurringsugars or modified sugars. Representative modified sugars includecarbocyclic or acyclic sugars, sugars having substituent groups at oneor more of their 2′, 3′ or 4′ positions and sugars having substituentsin place of one or more hydrogen atoms of the sugar. In certainembodiments, the sugar is modified by having a substituent group at the2′ position. In additional embodiments, the sugar is modified by havinga substituent group at the 3′ position. In other embodiments, the sugaris modified by having a substituent group at the 4′ position. It is alsocontemplated that a sugar may have a modification at more than one ofthose positions, or that an RNA molecule may have one or morenucleotides with a sugar modification at one position and also one ormore nucleotides with a sugar modification at a different position.

Sugar modifications contemplated in miRNA mimics include, but are notlimited to, a sugar substituent group selected from: OH; F; O-, S-, orN-alkyl; O-, S-, or N-alkenyl; O-, S- or N-alkynyl; or O-alkyl-O-alkyl,wherein the alkyl, alkenyl and alkynyl may be substituted orunsubstituted C₁ to C₁₀ alkyl or C₂ to C₁₀ alkenyl and alkynyl. In someembodiments, these groups may be chosen from: O(CH₂)_(x)OCH₃,O((CH₂)_(x)O)_(y)CH₃, O(CH₂)_(x)NH₂, O(CH₂)_(x)CH₃, O(CH₂)_(x)ONH₂, andO(CH₂)_(x)ON((CH₂)_(x)CH₃)₂, where x and y are from 1 to 10.

In some embodiments, miRNA mimics have a sugar substituent groupselected from the following: C₁ to C₁₀ lower alkyl, substituted loweralkyl, alkenyl, alkynyl, alkaryl, aralkyl, O-alkaryl or O-aralkyl, SH,SCH₃, Cl, Br, CN, OCN, CF₃, OCF₃, SOCH₃, SO₂CH₃, ONO₂, NO₂, N₃, NH₂,heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, polyalkylamino,substituted silyl, an RNA cleaving group, a reporter group, anintercalator, a group for improving the pharmacokinetic properties of amimic, or a group for improving the pharmacodynamic properties of amimic, and other substituents having similar properties. In oneembodiment, the modification includes 2′-methoxyethoxy (2′-O—CH₂CH₂OCH₃,which is also known as 2′-O-(2-methoxyethyl) or 2′-MOE) (Martin et al.,Hely. Chim. Acta, 78, 486-504, 1995,), that is, an alkoxyalkoxy group.Another modification includes 2′-dimethylaminooxyethoxy, that is, aO(CH₂)₂ON(CH₃)₂ group, also known as 2′-DMAOE and2′-dimethylaminoethoxyethoxy (also known in the art as2′-O-dimethyl-amino-ethoxy-ethyl or T-DMAEOE), that is,2′-O—CH₂—O—CH₂—N(CH₃)₂.

Additional sugar substituent groups include allyl (—CH₂—CH═CH₂),—O-allyl (—O—CH₂—CH═CH₂), methoxy (—O—CH₃), aminopropoxy(—OCH₂CH₂CH₂NH₂), and fluoro (F). Sugar substituent groups on the 2′position (2′-) may be in the arabino (up) position or ribo (down)position. One 2′-arabino modification is 2′-F. Other similarmodifications may also be made at other positions on the oligomericcompound, particularly the 3′ position of the sugar on the 3′ terminalnucleoside or in 2′-5′ linked oligonucleotides and the 5′ position of 5′terminal nucleotide. Oligomeric compounds may also have sugar mimetics,for example, cyclobutyl moieties, in place of the pentofuranosyl sugar.Examples of U.S. patents that disclose the preparation of modified sugarstructures include, but are not limited to, U.S. Pat. Nos. 4,981,957;5,118,800; 5,319,080; 5,359,044; 5,393,878; 5,446,137; 5,466,786;5,514,785; 5,519,134; 5,567,811; 5,576,427; 5,591,722; 5,597,909;5,610,300; 5,627,053; 5,639,873; 5,646,265; 5,658,873; 5,670,633;5,792,747; and 5,700,920, which are herein incorporated by reference inits entirety.

Representative sugar substituent groups include groups described in U.S.Patent Application Publication 2005/0261218, which is herebyincorporated by reference. In particular embodiments, the sugarmodification is a 2′O-Me modification, a 2′F modification, a 2′Hmodification, a 2′ amino modification, a 4′ thioribose modification or aphosphorothioate modification on the carboxy group linked to the carbonat position 6′, or combinations thereof.

Additional modifications are disclosed in U.S. Patent ApplicationPublication 2010/0267814, which is hereby incorporated by reference.While this references discloses general modifications that might bemade, it does not disclose what is set forth herein that modificationsmight be made in the context of a particular sequence at specificnucleotides and/or in specific and select positions.

In some embodiments, a therapeutic nucleic acid contains one or moredesign elements. These design elements include, but are not limited to:(i) a replacement group for the phosphate or hydroxyl of the nucleotideor nucleoside, respectively, at the 5′ terminus of the complementaryregion; (ii) one or more sugar modifications in the first or last 1 to 6residues of the complementary region; or, (iii) non-complementaritybetween one or more nucleotides in the last 1 to 5 residues at the 3′end of the complementary region and the corresponding nucleotides of themiRNA region.

In certain embodiments, a synthetic miRNA has a nucleotide at its 5′ endof the complementary region in which the phosphate and/or hydroxyl grouphas been replaced with another chemical group (referred to as the“replacement design”). In some cases, the phosphate group is replaced oradded onto with an additional moiety, while in others, the hydroxylgroup has been replaced or added onto with an additional moiety, such asdescribed above with the C6 amine linker. In particular embodiments, themoiety is biotin, an amine group, a lower alkylamine group, an acetylgroup, 2′O-Me (2′ oxygen-methyl), DMTO (4,4′-dimethoxytrityl withoxygen), fluorescein, a thiol, or acridine, though other moieties arewell known to those of skill in the art and can be used as well.

In other embodiments of the invention, there is a synthetic miRNA inwhich one or more nucleotides in the last 1 to 5 residues at the 3′ endof the complementary region are not complementary to the correspondingnucleotides of the miRNA region (“non-complementarity”) (referred to asthe “non-complementarity design”). The non-complementarity may be in thelast 1, 2, 3, 4, and/or 5 residues of the complementary miRNA. Incertain embodiments, there is non-complementarity with at least 2nucleotides in the complementary region.

It is contemplated that synthetic miRNA of the invention have one ormore of the replacement, sugar modification, or non-complementaritydesigns. In certain cases, synthetic RNA molecules have two of them,while in others these molecules have all three designs in place.

The miRNA region and the complementary region may be on the same orseparate polynucleotides. In cases in which they are contained on or inthe same polynucleotide, the miRNA molecule will be considered a singlepolynucleotide. In embodiments in which the different regions are onseparate polynucleotides, the synthetic miRNA will be considered to becomprised of two polynucleotides.

When the RNA molecule is a single polynucleotide, there is a linkerregion between the miRNA region and the complementary region. In someembodiments, the single polynucleotide is capable of forming a hairpinloop structure as a result of bonding between the miRNA region and thecomplementary region. The linker constitutes the hairpin loop. It iscontemplated that in some embodiments, the linker region is, is atleast, or is at most 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, or 40 residues in length, or any range derivabletherein. In certain embodiments, the linker is between 3 and 30 residues(inclusive) in length.

In addition to having a miRNA region and a complementary region, theremay be flanking sequences as well at either the 5′ or 3′ end of theregion. In some embodiments, there is or is at least 1, 2, 3, 4, 5, 6,7, 8, 9, 10 nucleotides or more, or any range derivable therein,flanking one or both sides of these regions.

RNA molecules with miRNA function may be, be at least, or be at most 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94,95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240,250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380,390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520,530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660,670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, 800,810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940,950, 960, 970, 980, 990, or 1000 nucleotides, or any range derivabletherein, in length. Such lengths cover the lengths of processed miRNA,miRNA probes, precursor miRNA, miRNA containing vectors, control nucleicacids, and other probes and primers. In many embodiments, miRNA are19-24 nucleotides in length, while miRNA probes are 5, 10, 15, 20, 25,30, to 35 nucleotides in length, including all values and ranges therebetween, depending on the length of the processed miRNA and any flankingregions added. miRNA precursors are generally between 62 and 110nucleotides in humans.

Nucleic acids of the invention may have regions of identity orcomplementarity to another nucleic acid. It is contemplated that theregion of complementarity or identity can be at least 5 contiguousresidues, though it is specifically contemplated that the region is, isat least, or is at most 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72,73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,91, 92, 93, 94, 95, 96, 97, 98, 99, 100, or 110 contiguous nucleotides.It is further understood that the length of complementarity within aprecursor miRNA or between a miRNA probe and a miRNA or a miRNA gene aresuch lengths. Moreover, the complementarity may be expressed as apercentage, meaning that the complementarity between a probe and itstarget is at least 90% identical or greater over the length of theprobe. In some embodiments, complementarity is or is at least 90%, 95%or 100% identical. In particular, such lengths may be applied to anynucleic acid comprising a nucleic acid sequence identified in any of SEQID NOs disclosed herein.

The term “recombinant” may be used and this generally refers to amolecule that has been manipulated in vitro or that is a replicated orexpressed product of such a molecule.

The term “miRNA” generally refers to an RNA molecule having a sequenceand function of an miRNA molecule. In specific embodiments, moleculesimplemented in the invention will also encompass a region or anadditional strand that is partially (between 10 and 50% complementaryacross length of strand), substantially (greater than 50% but less than100% complementary across length of strand) or fully complementary toanother region of the same single-stranded molecule or to anothernucleic acid. Thus, nucleic acids may encompass a molecule thatcomprises one or more complementary or self-complementary strand(s) or“complement(s)” of a particular sequence comprising a molecule. Forexample, precursor miRNA may have a self-complementary region, which isup to 100% complementary. miRNA probes or nucleic acids of the inventioncan include, can be or can be at least 60, 65, 70, 75, 80, 85, 90, 95,96, 97, 98, 99 or 100% complementary to their target.

Nucleic acids of the invention may be made by any technique known to oneof ordinary skill in the art, such as for example, chemical synthesis,enzymatic production or biological production. It is specificallycontemplated that miRNA probes of the invention are chemicallysynthesized.

In some embodiments of the invention, miRNAs are recovered or isolatedfrom a biological sample. The miRNA may be recombinant or it may benatural or endogenous to the cell (produced from the cell's genome). Itis contemplated that a biological sample may be treated in a way so asto enhance the recovery of small RNA molecules such as miRNA. U.S.patent application Ser. No. 10/667,126 describes such methods and it isspecifically incorporated by reference herein. Generally, methodsinvolve lysing cells with a solution having guanidinium and a detergent.

In certain aspects, synthetic miRNA are RNA or RNA analogs. miRNA mimicsmay be DNA and/or RNA, or analogs thereof. miRNA mimics with chemicalmodifications may be collectively referred to as “synthetic nucleicacids.”

In some embodiments, a therapeutic nucleic acid can have a miRNA or asynthetic miRNA sequence of between 10-200 to between 17-130 residues,including all values and ranges there between. The present inventionconcerns miRNA or synthetic miRNA molecules that are, are at least, orare at most 10, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46,47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64,65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82,83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100,101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114,115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,129, 130, 140, 150, 160, 170, 180, 190, 200 or more residues in length,including any integer or any range there between.

In certain aspects, synthetic nucleic acids have (a) a “miRNA region”whose sequence or binding region from 5′ to 3′ is identical orcomplementary to all or a segment of a mature miRNA sequence, and (b) a“complementary region” whose sequence from 5′ to 3′ is between 60% and100% complementary to the miRNA sequence in (a). In certain embodiments,these synthetic nucleic acids are also isolated, as defined below. Theterm “miRNA region” refers to a region on the synthetic nucleic acidthat is at least 75, 80, 85, 90, 95, or 100% identical, including allintegers there between, to the entire sequence of a mature, naturallyoccurring miRNA sequence or a complement thereof. In certainembodiments, the miRNA region is or is at least 90, 91, 92, 93, 94, 95,96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, 99.9 or100% identical to the sequence of a naturally-occurring miRNA, orsegment thereof, or complement thereof.

Discussed herein are embodiments involving miR-124 mimics. Differentactive and passenger strands for these mimics are described throughoutthe disclosure. It is contemplated that embodiments discussed in thecontext of a particular SEQ ID NO may be implemented in addition to orinstead of other embodiments discussing the same SEQ ID NO. For example,an active strand that has at least 90% identity to SEQ ID NO:2 and alsohas a substitution of one of the nucleotides/nucleoside may be combinedwith an embodiment of an active strand involving SEQ ID NO:2 that alsohas an insertion in the sequence; accordingly, an active strand that hasat least 90% identity to SEQ ID NO:2 would have both a substitution andan insertion with respect to SEQ ID NO:5.

It is contemplated that an RNA molecule may contain an active strandthat is or is at least 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100%identical, or any range derivable therein, to SEQ ID NO:1. In otherembodiments, the active strand is or is at least 90, 91, 92, 93, 94, 95,96, 97, 98, 99 or 100% identical, or any range derivable therein, to SEQID NO:2.

In some embodiments, an active strand is at least 95% identical to SEQID NO:1 (UAAGGCACGCGGUGAAUGCC). In certain embodiments, the activestrand has the following sequence from 5′ to 3′ in which one nucleotidefrom SEQ ID NO:1 is deleted:

UAAGGCACGCGGUGAAUGC (SEQ ID NO: 5) (C formerly at position 20 deleted)UAAGGCACGCGGUGAAUGC (SEQ ID NO: 5) (C formerly at position 19 deleted)UAAGGCACGCGGUGAAUCC (SEQ ID NO: 6) (G formerly at position 18 deleted)UAAGGCACGCGGUGAAGCC (SEQ ID NO: 7) (U formerly at position 17 deleted)UAAGGCACGCGGUGAUGCC (SEQ ID NO: 8) (A formerly at position 16 deleted)UAAGGCACGCGGUGAUGCC (SEQ ID NO: 8) (A formerly at position 15 deleted)UAAGGCACGCGGUAAUGCC (SEQ ID NO: 9) (G formerly at position 14 deleted)UAAGGCACGCGGGAAUGCC (SEQ ID NO: 10) (U formerly at position 13 deleted)UAAGGCACGCGUGAAUGCC (SEQ ID NO: 11) (G formerly at position 12 deleted)UAAGGCACGCGUGAAUGCC (SEQ ID NO: 11) (G formerly at position 11 deleted)UAAGGCACGGGUGAAUGCC (SEQ ID NO: 12) (C formerly at position 10 deleted)UAAGGCACCGGUGAAUGCC (SEQ ID NO: 13) (G formerly at position 9 deleted)UAAGGCAGCGGUGAAUGCC (SEQ ID NO: 14) (C formerly at position 8 deleted)UAAGGCCGCGGUGAAUGCC (SEQ ID NO: 15) (A formerly at position 7 deleted)UAAGGACGCGGUGAAUGCC (SEQ ID NO: 16) (C formerly at position 6 deleted)UAAGCACGCGGUGAAUGCC (SEQ ID NO: 17) (G formerly at position 5 deleted)UAAGCACGCGGUGAAUGCC (SEQ ID NO: 17) (G formerly at position 4 deleted)UAGGCACGCGGUGAAUGCC (SEQ ID NO: 18) (A formerly at position 3 deleted)UAGGCACGCGGUGAAUGCC (SEQ ID NO: 18) (A formerly at position 2 deleted)AAGGCACGCGGUGAAUGCC (SEQ ID NO: 19) (U formerly at position 1 deleted)

In embodiments where a nucleotide has been deleted relative to SEQ IDNO:1, it is contemplated that the designation of a modified nucleotidemay be adjusted accordingly. In some embodiments, it is contemplatedthat an active strand having a sequence that is at least 95% identicalto SEQ ID NO:1 has a modification of a nucleotide at one or more of thefollowing positions: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, or 21 with respect to either the 5′ or 3′ end of thestrand. In other embodiments, it is contemplated that an active strandmay have the following nucleotides modified: U at position 1 relative toSEQ ID NO:1; A at position 2 relative to SEQ ID NO:1; A at position 3relative to SEQ ID NO:1; G at position 4 relative to SEQ ID NO:1; G atposition 5 relative to SEQ ID NO:1; C at position 6 relative to SEQ IDNO:1; A at position 7 relative to SEQ ID NO:1; C at position 8 relativeto SEQ ID NO:1; G at position 9 relative to SEQ ID NO:1; C at position10 relative to SEQ ID NO:1; G at position 11 relative to SEQ ID NO:1; Gat position 12 relative to SEQ ID NO:1; U at position 13 relative to SEQID NO:1; G at position 14 relative to SEQ ID NO:1; A at position 15relative to SEQ ID NO:1; A at position 16 relative to SEQ ID NO:1; U atposition 17 relative to SEQ ID NO:1; G at position 18 relative to SEQ IDNO:1; C at position 19 relative to SEQ ID NO:1; and/or, C at position 20relative to SEQ ID NO:1. This means that the active strand may no longerhave the nucleotide at that position, but in the context of the sequenceof SEQ ID NO:1, the particular nucleotide in the active strand ismodified. This means its position may be altered by −1 or +1; forexample, the G at position 11 relative to SEQ ID NO:1, may be atposition 10 or at position 12 in the active strand because there hasbeen an insertion or deletion that affects its position number.

In some embodiments, an active strand is at least 95% identical to SEQID NO:2 (UUAAGGCACGCGGUGAAUGCCA), which is 2 bases longer than SEQ IDNO: 1. In certain embodiments, the active strand has the followingsequence from 5′ to 3′ in which one nucleotide from SEQ ID NO:2 isdeleted:

UUAAGGCACGCGGUGAAUGCC (SEQ ID NO: 20)(A formerly at position 22 deleted) UUAAGGCACGCGGUGAAUGCA(SEQ ID NO: 21) (C formerly at position 21 deleted)UUAAGGCACGCGGUGAAUGCA (SEQ ID NO: 21)(C formerly at position 20 deleted) UUAAGGCACGCGGUGAAUCCA(SEQ ID NO: 22) (G formerly at position 19 deleted)UUAAGGCACGCGGUGAAGCCA (SEQ ID NO: 23)(U formerly at position 18 deleted) UUAAGGCACGCGGUGAUGCCA(SEQ ID NO: 24) (A formerly at position 17 deleted)UUAAGGCACGCGGUGAUGCCA (SEQ ID NO: 24)(A formerly at position 16 deleted) UUAAGGCACGCGGUAAUGCCA(SEQ ID NO: 25) (G formerly at position 15 deleted)UUAAGGCACGCGGGAAUGCCA (SEQ ID NO: 26)(U formerly at position 14 deleted) UUAAGGCACGCGUGAAUGCCA(SEQ ID NO: 27) (G formerly at position 13 deleted)UUAAGGCACGCGUGAAUGCCA (SEQ ID NO: 27)(G formerly at position 12 deleted) UUAAGGCACGGGUGAAUGCCA(SEQ ID NO: 28) (C formerly at position 11 deleted)UUAAGGCACCGGUGAAUGCCA (SEQ ID NO: 29)(G formerly at position 10 deleted) UUAAGGCAGCGGUGAAUGCCA(SEQ ID NO: 30) (C formerly at position 9 deleted) UUAAGGCCGCGGUGAAUGCCA(SEQ ID NO: 31) (A formerly at position 8 deleted) UUAAGGACGCGGUGAAUGCCA(SEQ ID NO: 32) (C formerly at position 7 deleted) UUAAGCACGCGGUGAAUGCCA(SEQ ID NO: 33) (G formerly at position 6 deleted) UUAAGCACGCGGUGAAUGCCA(SEQ ID NO: 33) (G formerly at position 5 deleted) UUAGGCACGCGGUGAAUGCCA(SEQ ID NO: 34) (A formerly at position 4 deleted) UUAGGCACGCGGUGAAUGCCA(SEQ ID NO: 34) (A formerly at position 3 deleted) UAAGGCACGCGGUGAAUGCCA(SEQ ID NO:  35) (U formerly at position 2 deleted)UAAGGCACGCGGUGAAUGCCA (SEQ ID NO:  35)(U formerly at position 1 deleted)

In embodiments where a nucleotide has been deleted relative to SEQ IDNO:2, it is contemplated that the designation of a modified nucleotidemay be adjusted accordingly.

In some embodiments, it is contemplated that an active strand having asequence that is at least 95% identical to SEQ ID NO:2 has amodification of a nucleotide at one or more of the following positions:1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21 or 22 with respect to either the 5′ or 3′ end of the strand. In otherembodiments, it is contemplated that an active strand may have thefollowing nucleotides modified: U at position 1 relative to SEQ ID NO:2;U at position 2 relative to SEQ ID NO:2; A at position 3 relative to SEQID NO:2; A at position 4 relative to SEQ ID NO:2; G at position 5relative to SEQ ID NO:2; G at position 6 relative to SEQ ID NO:2; C atposition 7 relative to SEQ ID NO:2; A at position 8 relative to SEQ IDNO:2; C at position 9 relative to SEQ ID NO:2; G at position 10 relativeto SEQ ID NO:2; C at position 11 relative to SEQ ID NO:2; G at position12 relative to SEQ ID NO:2; G at position 13 relative to SEQ ID NO:12 Uat position 14 relative to SEQ ID NO:2; G at position 15 relative to SEQID NO:2; A at position 16 relative to SEQ ID NO:2; A at position 17relative to SEQ ID NO:2; U at position 18 relative to SEQ ID NO:2; G atposition 19 relative to SEQ ID NO:2; C at position 20 relative to SEQ IDNO:2; C at position 21 relative to SEQ ID NO:2; and/or, A at position 22relative to SEQ ID NO:2. This means that the active strand may no longerhave the nucleotide at that position, but in the context of the sequenceof SEQ ID NO:2, the particular nucleotide in the active strand ismodified. This means its position may be altered by −1 or −2; forexample, the C at position 11 relative to SEQ ID NO:2, may be atposition 10 in the active strand because there has been a deletion thataffects its position number.

In some embodiments, an active strand is 95% identical to SEQ ID NO:1(UAAGGCACGCGGUGAAUGCC). In certain embodiments such an active strand hasthe following sequence from 5′ to 3′ in which one nucleotide issubstituted with a different ribonucleotide (A, C, G, or U), asrepresented by N:

NAAGGCACGCGGUGAAUGCC (SEQ ID NO: 36) UNAGGCACGCGGUGAAUGCC(SEQ ID NO: 37) UANGGCACGCGGUGAAUGCC (SEQ ID NO: 38)UAANGCACGCGGUGAAUGCC (SEQ ID NO: 39) UAAGNCACGCGGUGAAUGCC(SEQ ID NO: 40) UAAGGNACGCGGUGAAUGCC (SEQ ID NO: 41)UAAGGCNCGCGGUGAAUGCC (SEQ ID NO: 42) UAAGGCANGCGGUGAAUGCC(SEQ ID NO: 43) UAAGGCACNCGGUGAAUGCC (SEQ ID NO: 44)UAAGGCACGNGGUGAAUGCC (SEQ ID NO: 45) UAAGGCACGCNGUGAAUGCC(SEQ ID NO: 46) UAAGGCACGCGNUGAAUGCC (SEQ ID NO: 47)UAAGGCACGCGGNGAAUGCC (SEQ ID NO: 48) UAAGGCACGCGGUNAAUGCC(SEQ ID NO: 49) UAAGGCACGCGGUGNAUGCC (SEQ ID NO: 50)UAAGGCACGCGGUGANUGCC (SEQ ID NO: 51) UAAGGCACGCGGUGAANGCC(SEQ ID NO: 52) UAAGGCACGCGGUGAAUNCC (SEQ ID NO: 53)UAAGGCACGCGGUGAAUGNC (SEQ ID NO: 54) UAAGGCACGCGGUGAAUGCN(SEQ ID NO: 55)

In some embodiments, an active strand is 95-100% identical to SEQ IDNO:1, which should include the sequences disclosed above. Other examplesof such active strands include active strands with an insertion of asingle nucleotide, as discussed below, in which the following sequencesfrom 5′ to 3′ have an insertion of a nucleotide designated as N, whichmay be an A, C, G, or U:

NUAAGGCACGCGGUGAAUGCC (SEQ ID NO: 56) UNAAGGCACGCGGUGAAUGCC(SEQ ID NO: 57) UANAGGCACGCGGUGAAUGCC (SEQ ID NO: 58)UAANGGCACGCGGUGAAUGCC (SEQ ID NO: 59) UAAGNGCACGCGGUGAAUGCC(SEQ ID NO: 60) UAAGGNCACGCGGUGAAUGCC (SEQ ID NO: 61)UAAGGCNACGCGGUGAAUGCC (SEQ ID NO: 62) UAAGGCANCGCGGUGAAUGCC(SEQ ID NO: 63) UAAGGCACNGCGGUGAAUGCC (SEQ ID NO: 64)UAAGGCACGNCGGUGAAUGCC (SEQ ID NO: 65) UAAGGCACGCNGGUGAAUGCC(SEQ ID NO: 66) UAAGGCACGCGNGUGAAUGCC (SEQ ID NO: 67)UAAGGCACGCGGNUGAAUGCC (SEQ ID NO: 68) UAAGGCACGCGGUNGAAUGCC(SEQ ID NO: 69) UAAGGCACGCGGUGNAAUGCC (SEQ ID NO: 70)UAAGGCACGCGGUGANAUGCC (SEQ ID NO: 71) UAAGGCACGCGGUGAANUGCC(SEQ ID NO: 72) UAAGGCACGCGGUGAAUNGCC (SEQ ID NO: 73)UAAGGCACGCGGUGAAUGNCC (SEQ ID NO: 74) UAAGGCACGCGGUGAAUGCNC(SEQ ID NO: 75) UAAGGCACGCGGUGAAUGCCN (SEQ ID NO: 76)

In some embodiments, in addition to the single insertion shown above,there is a second insertion or addition elsewhere in the sequencerelative to SEQ ID NO:1. In some embodiments, in addition to the singleinsertion shown above, there is a second insertion or addition elsewherein the sequence relative to SEQ ID NO: 1. It is contemplated that thesecond insertion may be after the nucleotide newly or previously locatedat position 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, or 23.

In some embodiments, an active strand is or ist at least 90% identicalto SEQ ID NO:2 (UUAAGGCACGCGGUGAAUGCCA). In certain embodiments, such anactive strand has the following sequence from 5′ to 3′ in which one ortwo nucleotides is substituted with a different ribonucleotide. Incertain embodiment there is one substitution as represented by N:

NUAAGGCACGCGGUGAAUGCCA (SEQ ID NO: 77) UNAAGGCACGCGGUGAAUGCCA(SEQ ID NO: 78) UUNAGGCACGCGGUGAAUGCCA (SEQ ID NO: 79)UUANGGCACGCGGUGAAUGCCA (SEQ ID NO: 80) UUAANGCACGCGGUGAAUGCCA(SEQ ID NO: 81) UUAAGNCACGCGGUGAAUGCCA (SEQ ID NO: 82)UUAAGGNACGCGGUGAAUGCCA (SEQ ID NO: 83) UUAAGGCNCGCGGUGAAUGCCA(SEQ ID NO: 84) UUAAGGCANGCGGUGAAUGCCA (SEQ ID NO: 85)UUAAGGCACNCGGUGAAUGCCA (SEQ ID NO: 86) UUAAGGCACGNGGUGAAUGCCA(SEQ ID NO: 87) UUAAGGCACGCNGUGAAUGCCA (SEQ ID NO: 88)UUAAGGCACGCGNUGAAUGCCA (SEQ ID NO: 89) UUAAGGCACGCGGNGAAUGCCA(SEQ ID NO: 90) UUAAGGCACGCGGUNAAUGCCA (SEQ ID NO: 91)UUAAGGCACGCGGUGNAUGCCA (SEQ ID NO: 92) UUAAGGCACGCGGUGANUGCCA(SEQ ID NO: 93) UUAAGGCACGCGGUGAANGCCA (SEQ ID NO: 94)UUAAGGCACGCGGUGAAUNCCA (SEQ ID NO: 95) UUAAGGCACGCGGUGAAUGNCA(SEQ ID NO: 96) UUAAGGCACGCGGUGAAUGCNA (SEQ ID NO: 97)UUAAGGCACGCGGUGAAUGCCN (SEQ ID NO: 98)

In some embodiments, in addition to the single substitution shown above,there is a second substitution elsewhere in the sequence relative to SEQID NO:2. It is further contemplated that there may be a secondsubstitution with one of the substitutions described in an active stranddescribed above, or one or two deletions of nucleotides in addition tothe substitution described above.

In some embodiments, an active strand is 95-100% identical to SEQ IDNO:2, which should include the sequences disclosed above. Other examplesof such active strands include active strands with an insertion of asingle nucleotide into the sequence of SEQ ID NO:2.

In certain embodiments, the active strand has a sequence that is or isat least 95% identical to SEQ ID NO:1 or SEQ ID NO:2. SEQ ID NO:1 (20nucleotides in length) is approximately 90.9% identical to SEQ ID NO:2(22 nucleotides in length), and a fragment of 20 contiguous nucleotidesin SEQ ID NO:2 is 100% identical to SEQ ID:1.

It is noted that in some embodiments the sequence of the active strandconsists of SEQ ID NO:1, which means the active strand has a sequencethat is 100% identical to SEQ ID NO:1. In other embodiments, thesequence of the active strand consists of SEQ ID NO:2, which means theactive strand has a sequence that is 100% identical to SEQ ID NO:2. Inany of these embodiments, it is contemplated that an active strand mayinclude a modification of a nucleotide located at position 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 171, 18, 19, 20, 21, and/or22 (where position 1 is the 5′ end of the strand) with respect to the 5′end of the active strand. This means the nucleotide at the recitedposition is modified, and this designation is independent of theidentity of the particular nucleotide at that recited position. Thisdesignation is position-based, as opposed to nucleotide-based. In otherembodiments, the designations are nucleotide-based. In certainembodiments, a designation may be position based with respect to the 3′end of the active strand; in such a case, the active strand may includea modification of a nucleotide located 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 171, 18, 19, 20, 21, and/or 22 nucleotides awayfrom the 3′ end of the active strand. Any embodiments discussed hereinin which a modified nucleotide was identified as nucleotide-based may beimplemented in other embodiments a modified nucleotide that isposition-based using the position of the identified nucleotide. Thisapplies to active strands, as well as passenger strands.

In some embodiments, nucleotide-based designations set forth that anactive strand may be modified at the following nucleotides: U atposition 1 in SEQ ID NO:2; U at position 1 in SEQ ID NO:1 and atposition 2 in SEQ ID NO:2; A at position 2 in SEQ ID NO:1 and atposition 3 in SEQ ID NO:2; A at position 3 in SEQ ID NO:1 and atposition 4 in SEQ ID NO:2; G at position 4 in SEQ ID NO:1 and atposition 5 in SEQ ID NO:2; G at position 5 in SEQ ID NO:1 and atposition 6 in SEQ ID NO:2; C at position 6 in SEQ ID NO:1 and atposition 7 in SEQ ID NO:2; A at position 7 in SEQ ID NO:1 and atposition 8 in SEQ ID NO:2; C at position 8 in SEQ ID NO:1 and atposition 9 in SEQ ID NO:2; G at position 9 in SEQ ID NO:1 and atposition 10 in SEQ ID NO:2; C at position 10 in SEQ ID NO:1 and atposition 11 in SEQ ID NO:2; G at position 11 in SEQ ID NO:1 and atposition 12 in SEQ ID NO:2; G at position 12 in SEQ ID NO:1 and atposition 13 in SEQ ID NO:2; U at position 13 in SEQ ID NO:1 and atposition 14 in SEQ ID NO:2; G at position 14 in SEQ ID NO:1 and atposition 15 in SEQ ID NO:2; A at position 15 in SEQ ID NO:1 and atposition 16 in SEQ ID NO:2; A at position 16 in SEQ ID NO:1 and atposition 17 in SEQ ID NO:2; U at position 17 in SEQ ID NO:1 and atposition 18 in SEQ ID NO:2; G at position 18 in SEQ ID NO:1 and atposition 19 in SEQ ID NO:2; C at position 19 in SEQ ID NO:1 and atposition 20 in SEQ ID NO:2; C at position 20 in SEQ ID NO:1 and atposition 21 in SEQ ID NO:2; and/or A at position 22 in SEQ ID NO:2.

In certain embodiments, the passenger strand has a sequence that is oris at least 95% identical to SEQ ID NO:3 or SEQ ID NO:4. SEQ ID NO:3 (20nucleotides in length) is approximately 90.9% identical to SEQ ID NO:4(22 nucleotides in length), and a fragment of 20 contiguous nucleotidesin SEQ ID NO:4 is 100% identical to SEQ ID:3.

It is noted that in some embodiments the sequence of the passengerstrand consists of SEQ ID NO:3, which means the passenger strand has asequence that is 100% identical to SEQ ID NO:3. In other embodiments,the sequence of the passenger strand consists of SEQ ID NO:4, whichmeans the passenger strand has a sequence that is 100% identical to SEQID NO:4. In any of these embodiments, it is contemplated that anpassenger strand may include a modification of a nucleotide located atposition 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 171, 18,19, 20, 21, and/or 22 (where position 1 is the 5′ end of the strand)with respect to the 5′ end of the passenger strand. This means thenucleotide at the recited position is modified, and this designation isindependent of the identity of the particular nucleotide at that recitedposition. This designation is position-based, as opposed tonucleotide-based. In other embodiments, the designations arenucleotide-based. In certain embodiments, a designation may be positionbased with respect to the 3′ end of the passenger strand; in such acase, the passenger strand may include a modification of a nucleotidelocated 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 171, 18,19, 20, 21, and/or 22 nucleotides away from the 3′ end of the passengerstrand.

It is contemplated that an RNA molecule may contain a passenger strandthat is or is at least 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100%identical, or any range derivable therein, to SEQ ID NO:3. In otherembodiments, a passenger strand is or is at least 90, 91, 92, 93, 94,95, 96, 97, 98, 99 or 100% identical, or any range derivable therein, toSEQ ID NO:4.

In some embodiments, a passenger strand is 95% identical to SEQ ID NO:3(GGCAUUCACCGCGUGCCUUA). In certain embodiments, the active strand hasthe following sequence from 5′ to 3′ in which one nucleotide from SEQ IDNO:1 is deleted:

GGCAUUCACCGCGUGCCUU (SEQ ID NO: 99) (A formerly at position 20 deleted)GGCAUUCACCGCGUGCCUA (SEQ ID NO: 100) (U formerly at position 19 deleted)GGCAUUCACCGCGUGCCUA (SEQ ID NO: 100) (U formerly at position 18 deleted)GGCAUUCACCGCGUGCUUA (SEQ ID NO: 101) (C formerly at position 17 deleted)GGCAUUCACCGCGUGCUUA (SEQ ID NO: 101) (C formerly at position 16 deleted)GGCAUUCACCGCGUCCUUA (SEQ ID NO: 102) (G formerly at position 15 deleted)GGCAUUCACCGCGGCCUUA (SEQ ID NO: 103) (U formerly at position 14 deleted)GGCAUUCACCGCUGCCUUA (SEQ ID NO: 104) (G formerly at position 13 deleted)GGCAUUCACCGGUGCCUUA (SEQ ID NO: 105) (C formerly at position 12 deleted)GGCAUUCACCCGUGCCUUA (SEQ ID NO: 106) (G formerly at position 11 deleted)GGCAUUCACGCGUGCCUUA (SEQ ID NO: 107) (C formerly at position 10 deleted)GGCAUUCACGCGUGCCUUA (SEQ ID NO: 107) (C formerly at position 9 deleted)GGCAUUCCCGCGUGCCUUA (SEQ ID NO: 108) (A formerly at position 8 deleted)GGCAUUACCGCGUGCCUUA (SEQ ID NO: 109) (C formerly at position 7 deleted)GGCAUCACCGCGUGCCUUA (SEQ ID NO: 110) (U formerly at position 6 deleted)GGCAUCACCGCGUGCCUUA (SEQ ID NO: 110) (U formerly at position 5 deleted)GGCUUCACCGCGUGCCUUA (SEQ ID NO: 111) (A formerly at position 4 deleted)GGAUUCACCGCGUGCCUUA (SEQ ID NO: 112) (C formerly at position 3 deleted)GCAUUCACCGCGUGCCUUA (SEQ ID NO: 113) (G formerly at position 2 deleted)GCAUUCACCGCGUGCCUUA (SEQ ID NO: 113) (G formerly at position 1 deleted)

In embodiments where a nucleotide has been deleted relative to SEQ IDNO:3, it is contemplated that the designation of a modified nucleotidemay be adjusted accordingly.

In some embodiments, it is contemplated that an active strand having asequence that is at least 95% identical to SEQ ID NO:3 has amodification of a nucleotide at one or more of the following positions:1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,or 21 with respect to either the 5′ or 3′ end of the strand: G atposition 1 relative to SEQ ID NO:3; G at position 2 relative to SEQ IDNO:3; C at position 3 relative to SEQ ID NO:3; A at position 4 relativeto SEQ ID NO:3; U at position 5 relative to SEQ ID NO:3; U at position 6relative to SEQ ID NO:3; C at position 7 relative to SEQ ID NO:3; A atposition 8 relative to SEQ ID NO:3; C at position 9 relative to SEQ IDNO:3; C at position 2 relative to SEQ ID NO:10; G at position 11relative to SEQ ID NO:3; C at position 12 relative to SEQ ID NO:3; G atposition 13 relative to SEQ ID NO:3; U at position 14 relative to SEQ IDNO:3; G at position 15 relative to SEQ ID NO:3; C at position 16relative to SEQ ID NO:3; C at position 17 relative to SEQ ID NO:3; U atposition 18 relative to SEQ ID NO:3; U at position 19 relative to SEQ IDNO:3; and/or, A at position 20 relative to SEQ ID NO:3. This means thatthe passenger strand may no longer have the nucleotide at that position,but in the context of the sequence of SEQ ID NO:3, the particularnucleotide in the active strand is modified. This means its position maybe altered by −1 or +1; for example, the G at position 11 relative toSEQ ID NO:3, may be at position 10 or at position 12 in a passengerstrand because there has been an insertion or deletion that affects itsposition number.

In some embodiments, a passenger strand is 95% identical to SEQ ID NO:4(UGGCAUUCACCGCGUGCCUUAA), which is 2 bases longer than SEQ ID NO:3. Incertain embodiments, the passenger strand has the following sequencefrom 5′ to 3′ in which one nucleotide from SEQ ID NO:4 is deleted:

UGGCAUUCACCGCGUGCCUUA (SEQ ID NO: 114)(A formerly at position 22 deleted) UGGCAUUCACCGCGUGCCUUA(SEQ ID NO: 114) (A formerly at position 21 deleted)UGGCAUUCACCGCGUGCCUAA (SEQ ID NO: 115)(U formerly at position 20 deleted) UGGCAUUCACCGCGUGCCUAA(SEQ ID NO: 115) (U formerly at position 19 deleted)UGGCAUUCACCGCGUGCUUAA (SEQ ID NO: 116)(C formerly at position 18 deleted) UGGCAUUCACCGCGUGCUUAA(SEQ ID NO: 116) (C formerly at position 17 deleted)UGGCAUUCACCGCGUCCUUAA (SEQ ID NO: 117)(G formerly at position 16 deleted) UGGCAUUCACCGCGGCCUUAA(SEQ ID NO: 118) (U formerly at position 15 deleted)UGGCAUUCACCGCUGCCUUAA (SEQ ID NO: 119)(G formerly at position 14 deleted) UGGCAUUCACCGGUGCCUUAA(SEQ ID NO: 120) (C formerly at position 13 deleted)UGGCAUUCACCCGUGCCUUAA (SEQ ID NO: 121)(G formerly at position 12 deleted) UGGCAUUCACGCGUGCCUUAA(SEQ ID NO: 122) (C formerly at position 11 deleted)UGGCAUUCACGCGUGCCUUAA (SEQ ID NO: 122)(C formerly at position 10 deleted) UGGCAUUCCCGCGUGCCUUAA(SEQ ID NO: 123) (A formerly at position 9 deleted)UGGCAUUACCGCGUGCCUUAA (SEQ ID NO: 124)(C formerly at position 8 deleted) UGGCAUCACCGCGUGCCUUAA(SEQ ID NO: 125) (U formerly at position 7 deleted)UGGCAUCACCGCGUGCCUUAA (SEQ ID NO: 125)(U formerly at position 6 deleted) UGGCUUCACCGCGUGCCUUAA(SEQ ID NO: 126) (A formerly at position 5 deleted)UGGAUUCACCGCGUGCCUUAA (SEQ ID NO: 127)(C formerly at position 4 deleted) UGCAUUCACCGCGUGCCUUAA(SEQ ID NO: 128) (G formerly at position 3 deleted)UGCAUUCACCGCGUGCCUUAA (SEQ ID NO: 129)(G formerly at position 2 deleted) GGCAUUCACCGCGUGCCUUAA(SEQ ID NO: 130) (U formerly at position 1 deleted)

In embodiments where a nucleotide has been deleted relative to SEQ IDNO:4, it is contemplated that the designation of a modified nucleotidemay be adjusted accordingly. In some embodiments, it is contemplatedthat an active strand having a sequence that is at least 95% identicalto SEQ ID NO:4 has a modification of a nucleotide at one or more of thefollowing positions: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21 or 22 with respect to either the 5′ or 3′ end ofthe strand. In other embodiments, it is contemplated that an activestrand may have the following nucleotides modified:

U at position 1 relative to SEQ ID NO:4; G at position 2 relative to SEQID NO:4; G at position 3 relative to SEQ ID NO:4; C at position 4relative to SEQ ID NO:4; A at position 5 relative to SEQ ID NO:4; U atposition 6 relative to SEQ ID NO:4; U at position 7 relative to SEQ IDNO:4; C at position 8 relative to SEQ ID NO:4; A at position 9 relativeto SEQ ID NO:4; C at position 10 relative to SEQ ID NO:4; C at position11 relative to SEQ ID NO:4; G at position 12 relative to SEQ ID NO:4; Cat position 13 relative to SEQ ID NO:4; G at position 14 relative to SEQID NO:4; U at position 15 relative to SEQ ID NO:4; G at position 16relative to SEQ ID NO:4; C at position 17 relative to SEQ ID NO:4; C atposition 18 relative to SEQ ID NO:4; U at position 19 relative to SEQ IDNO:4; U at position 20 relative to SEQ ID NO:4; A at position 21relative to SEQ ID NO:4; and/or A at position 20 relative to SEQ IDNO:4. This means that the active strand may no longer have thenucleotide at that position, but in the context of the sequence of SEQID NO:2, the particular nucleotide in the active strand is modified.This means its position may be altered by −1 or −2; for example, the Cat position 11 relative to SEQ ID NO:2, may be at position 10 in theactive strand because there has been a deletion that affects itsposition number.

In some embodiments, a passenger strand is 95% identical to SEQ ID NO:3(GGCAUUCACCGCGUGCCUUA). In certain embodiments such a passenger strandhas the following sequence from 5′ to 3′ in which one nucleotide issubstituted with a different ribonucleotide (A, C, G, or U), asrepresented by N:

NGCAUUCACCGCGUGCCUUA (SEQ ID NO: 131) GNCAUUCACCGCGUGCCUUA(SEQ ID NO: 132) GGNAUUCACCGCGUGCCUUA (SEQ ID NO: 133)GGCNUUCACCGCGUGCCUUA (SEQ ID NO: 134) GGCANUCACCGCGUGCCUUA(SEQ ID NO: 135) GGCAUNCACCGCGUGCCUUA (SEQ ID NO: 136)GGCAUUNACCGCGUGCCUUA (SEQ ID NO: 137) GGCAUUCNCCGCGUGCCUUA(SEQ ID NO: 138) GGCAUUCANCGCGUGCCUUA (SEQ ID NO: 139)GGCAUUCACNGCGUGCCUUA (SEQ ID NO: 140) GGCAUUCACCNCGUGCCUUA(SEQ ID NO: 141) GGCAUUCACCGNGUGCCUUA (SEQ ID NO: 142)GGCAUUCACCGCNUGCCUUA (SEQ ID NO: 143) GGCAUUCACCGCGNGCCUUA(SEQ ID NO: 144) GGCAUUCACCGCGUNCCUUA (SEQ ID NO: 145)GGCAUUCACCGCGUGNCUUA (SEQ ID NO: 146) GGCAUUCACCGCGUGCNUUA(SEQ ID NO: 147) GGCAUUCACCGCGUGCCNUA (SEQ ID NO: 148)GGCAUUCACCGCGUGCCUNA (SEQ ID NO: 149) GGCAUUCACCGCGUGCCUUN(SEQ ID NO: 150)

In some embodiments, in addition to the single substitution shown above,there is a second substitution elsewhere in the sequence relative to SEQID NO:3. It is further contemplated that there may be a secondsubstitution with one of the substitutions described in a passengerstrand described above, or one or two deletions of nucleotides inaddition to the substitution described above.

In some embodiments, a passenger strand is 95-100% identical to SEQ IDNO:3, which should include the sequences disclosed above. Other examplesof such active strands include active strands with an insertion of asingle nucleotide, as discussed below, in which the following sequencesfrom 5′ to 3′ have an insertion of a nucleotide designated as N, whichmay be an A, C, G, or U:

NGGCAUUCACCGCGUGCCUUA (SEQ ID NO: 151) GNGCAUUCACCGCGUGCCUUA(SEQ ID NO: 152) GGNCAUUCACCGCGUGCCUUA (SEQ ID NO: 153)GGCNAUUCACCGCGUGCCUUA (SEQ ID NO: 154) GGCANUUCACCGCGUGCCUUA(SEQ ID NO: 155) GGCAUNUCACCGCGUGCCUUA (SEQ ID NO: 156)GGCAUUNCACCGCGUGCCUUA (SEQ ID NO: 157) GGCAUUCNACCGCGUGCCUUA(SEQ ID NO: 158) GGCAUUCANCCGCGUGCCUUA (SEQ ID NO: 159)GGCAUUCACNCGCGUGCCUUA (SEQ ID NO: 160) GGCAUUCACCNGCGUGCCUUA(SEQ ID NO: 161) GGCAUUCACCGNCGUGCCUUA (SEQ ID NO: 162)GGCAUUCACCGCNGUGCCUUA (SEQ ID NO: 163) GGCAUUCACCGCGNUGCCUUA(SEQ ID NO: 164) GGCAUUCACCGCGUNGCCUUA (SEQ ID NO: 165)GGCAUUCACCGCGUGNCCUUA (SEQ ID NO: 166) GGCAUUCACCGCGUGCNCUUA(SEQ ID NO: 167) GGCAUUCACCGCGUGCCNUUA (SEQ ID NO: 168)GGCAUUCACCGCGUGCCUNUA (SEQ ID NO: 169) GGCAUUCACCGCGUGCCUUNA(SEQ ID NO: 170) GGCAUUCACCGCGUGCCUUAN (SEQ ID NO: 171)

In some embodiments, in addition to the insertion in the passengerstrand shown above relative to SEQ ID NO:3, there may be a secondinsertion elsewhere in the strand. Combinations of insertions in thepassengers strands shown above are also contemplated for additionalpassenger strands.

In some embodiments, a passenger strand is or is at least 90% identicalto SEQ ID NO:4 (UGGCAUUCACCGCGUGCCUUAA). In certain embodiments, such apassenger strand has the following sequence from 5′ to 3′ in which oneor two nucleotides is substituted with a different ribonucleotide. Incertain embodiment there is one substitution as represented by N:

NGGCAUUCACCGCGUGCCUUAA (SEQ ID NO: 172) UNGCAUUCACCGCGUGCCUUAA(SEQ ID NO: 173) UGNCAUUCACCGCGUGCCUUAA (SEQ ID NO: 174)UGGNAUUCACCGCGUGCCUUAA (SEQ ID NO: 175) UGGCNUUCACCGCGUGCCUUAA(SEQ ID NO: 176) UGGCANUCACCGCGUGCCUUAA (SEQ ID NO: 177)UGGCAUNCACCGCGUGCCUUAA (SEQ ID NO: 178) UGGCAUUNACCGCGUGCCUUAA(SEQ ID NO: 179) UGGCAUUCNCCGCGUGCCUUAA (SEQ ID NO: 180)UGGCAUUCANCGCGUGCCUUAA (SEQ ID NO: 181) UGGCAUUCACNGCGUGCCUUAA(SEQ ID NO: 182) UGGCAUUCACCNCGUGCCUUAA (SEQ ID NO: 183)UGGCAUUCACCGNGUGCCUUAA (SEQ ID NO: 184) UGGCAUUCACCGCNUGCCUUAA(SEQ ID NO: 185) UGGCAUUCACCGCGNGCCUUAA (SEQ ID NO: 186)UGGCAUUCACCGCGUNCCUUAA (SEQ ID NO: 187) UGGCAUUCACCGCGUGNCUUAA(SEQ ID NO: 188) UGGCAUUCACCGCGUGCNUUAA (SEQ ID NO: 189)UGGCAUUCACCGCGUGCCNUAA (SEQ ID NO: 190) UGGCAUUCACCGCGUGCCUNAA(SEQ ID NO: 191) UGGCAUUCACCGCGUGCCUUNA (SEQ ID NO: 192)UGGCAUUCACCGCGUGCCUUAN (SEQ ID NO: 193)

In some embodiments, in addition to the single substitution shown above,there is a second substitution elsewhere in the sequence relative to SEQID NO:4. Moreover, any combination of substitutions shown above in thepassenger strands is contemplated.

In some embodiments, a passenger strand is 95-100% identical to SEQ IDNO:4, which should include the sequences disclosed above. Other examplesof such passenger strands include passenger strands with an insertion ofa single nucleotide into the sequence of SEQ ID NO:4.

It is noted that in some embodiments the sequence of the passengerstrand consists of SEQ ID NO:3, which means the passenger strand has asequence that is 100% identical to SEQ ID NO:3. In other embodiments,the sequence of the passenger strand consists of SEQ ID NO:4, whichmeans the passenger strand has a sequence that is 100% identical to SEQID NO:4. In any of these embodiments, it is contemplated that apassenger strand may include a modification of a nucleotide located atposition 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 171, 18,19, 20, 21, and/or 22 (where position 1 is the 5′ end of the strand)with respect to the 5′ end of the passenger strand. This means thenucleotide at the recited position is modified, and this designation isindependent of the identity of the particular nucleotide at that recitedposition. This designation is position-based, as opposed tonucleotide-based. In other embodiments, the designations arenucleotide-based. In certain embodiments, a designation may be positionbased with respect to the 3′ end of the passenger strand; in such acase, the passenger strand may include a modification of a nucleotidelocated 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 171, 18,19, 20, 21, and/or 22 nucleotides away from the 3′ end of the passengerstrand.

In some embodiments, nucleotide-based designations set forth that apassenger strand may be modified at the following nucleotides: U atposition 1 in SEQ ID NO:4; G at position 2 in SEQ ID NO:4; G at position3 in SEQ ID NO:4; C at position 4 in SEQ ID NO:4; A at position 5 in SEQID NO:4; U at position 6 in SEQ ID NO:4; U at position 7 in SEQ ID NO:4;C at position 8 in SEQ ID NO:4; A at position 9 in SEQ ID NO:4; C atposition 10 in SEQ ID NO:4; C at position 11 in SEQ ID NO:4; G atposition 12 in SEQ ID NO:4; C at position 13 in SEQ ID NO:4; G atposition 14 in SEQ ID NO:4; U at position 15 in SEQ ID NO:4; G atposition 16 in SEQ ID NO:4; C at position 17 in SEQ ID NO:4; C atposition 18 in SEQ ID NO:4; U at position 19 in SEQ ID NO:4; U atposition 20 in SEQ ID NO:4; A at position 21 in SEQ ID NO:4; and/or, Aat position 22 in SEQ ID NO:4.

The term “complementary region” or “complement” refers to a region of anucleic acid or mimic that is or is at least 60% complementary to themature, naturally occurring miRNA sequence. The complementary region isor is at least 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,92, 93, 94, 95, 96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6,99.7, 99.8, 99.9 or 100% complementary, or any range derivable therein.With single polynucleotide sequences, there may be a hairpin loopstructure as a result of chemical bonding between the miRNA region andthe complementary region. In other embodiments, the complementary regionis on a different nucleic acid molecule than the miRNA region, in whichcase the complementary region is on the complementary strand and themiRNA region is on the active strand.

When the RNA molecule is a single polynucleotide, there can be a linkerregion between the miRNA region and the complementary region. In someembodiments, the single polynucleotide is capable of forming a hairpinloop structure as a result of bonding between the miRNA region and thecomplementary region. The linker constitutes the hairpin loop. It iscontemplated that in some embodiments, the linker region is, is atleast, or is at most 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, or 40 residues in length, or any range derivabletherein. In certain embodiments, the linker is between 3 and 30 residues(inclusive) in length.

A. Isolation of Nucleic Acids

Nucleic acids may be isolated using techniques well known to those ofskill in the art, though in particular embodiments, methods forisolating small nucleic acid molecules, and/or isolating RNA moleculescan be employed. Chromatography is a process often used to separate orisolate nucleic acids from protein or from other nucleic acids. Suchmethods can involve electrophoresis with a gel matrix, filter columns,capillary electrophoresis, alcohol precipitation, and/or otherchromatography. If miRNA from cells is to be used or evaluated, methodsgenerally involve lysing the cells with a chaotropic agent (e.g.,guanidinium isothiocyanate) and/or detergent (e.g., N-lauroyl sarcosine)prior to implementing processes for isolating particular populations ofRNA.

In particular methods for separating miRNA from other nucleic acids, agel matrix is prepared using polyacrylamide, though agarose can also beused. The gels may be graded by concentration or they may be uniform.Plates or tubing can be used to hold the gel matrix for electrophoresis.Usually one-dimensional electrophoresis is employed for the separationof nucleic acids. Plates are used to prepare a slab gel, while thetubing (glass or rubber, typically) can be used to prepare a tube gel.The phrase “tube electrophoresis” refers to the use of a tube or tubing,instead of plates, to form the gel. Materials for implementing tubeelectrophoresis can be readily prepared by a person of skill in the artor purchased, such as from C.B.S. Scientific Co., Inc. or Scie-Plas.

Methods may involve the use of organic solvents and/or alcohol toisolate nucleic acids, particularly miRNA used in methods andcompositions of the invention. Some embodiments are described in U.S.patent application Ser. No. 10/667,126, which is hereby incorporated byreference. Generally, this disclosure provides methods for efficientlyisolating small RNA molecules from cells comprising: adding an alcoholsolution to a cell lysate and applying the alcohol/lysate mixture to asolid support before eluting the RNA molecules from the solid support.In some embodiments, the amount of alcohol added to a cell lysateachieves an alcohol concentration of about 55% to 60%. While differentalcohols can be employed, ethanol works well. A solid support may be anystructure, and it includes beads, filters, and columns, which mayinclude a mineral or polymer support with electronegative groups. Aglass fiber filter or column has worked particularly well for suchisolation procedures.

In specific embodiments, miRNA isolation processes include: a) lysingcells in the sample with a lysing solution comprising guanidinium,wherein a lysate with a concentration of at least about 1 M guanidiniumis produced; b) extracting miRNA molecules from the lysate with anextraction solution comprising phenol; c) adding to the lysate analcohol solution for form a lysate/alcohol mixture, wherein theconcentration of alcohol in the mixture is between about 35% to about70%; d) applying the lysate/alcohol mixture to a solid support; e)eluting the miRNA molecules from the solid support with an ionicsolution; and, f) capturing the miRNA molecules. Typically the sample isdried down and resuspended in a liquid and volume appropriate forsubsequent manipulation.

B. Preparation of Nucleic Acids

Alternatively, nucleic acid synthesis is performed according to standardmethods. See, for example, Itakura and Riggs (1980). Additionally, U.S.Pat. Nos. 4,704,362, 5,221,619, and 5,583,013 each describe variousmethods of preparing synthetic nucleic acids. Non-limiting examples of asynthetic nucleic acid (e.g., a synthetic oligonucleotide), include anucleic acid made by in vitro chemically synthesis usingphosphotriester, phosphite, or phosphoramidite chemistry and solid phasetechniques such as described in EP 266,032, incorporated herein byreference, or via deoxynucleoside H-phosphonate intermediates asdescribed by Froehler et al., 1986 and U.S. Pat. No. 5,705,629, eachincorporated herein by reference. In the methods described herein, oneor more oligonucleotide may be used. Oligonucleotide synthesis is wellknown to those of skill in the art. Various different mechanisms ofoligonucleotide synthesis have been disclosed in for example, U.S. Pat.Nos. 4,659,774, 4,816,571, 5,141,813, 5,264,566, 4,959,463, 5,428,148,5,554,744, 5,574,146, 5,602,244, each of which is incorporated herein byreference.

A non-limiting example of an enzymatically produced nucleic acidincludes one produced by enzymes in amplification reactions such as PCR™(see for example, U.S. Pat. Nos. 4,683,202 and 4,682,195, eachincorporated herein by reference), or the synthesis of anoligonucleotide described in U.S. Pat. No. 5,645,897, incorporatedherein by reference. Non-limiting examples of a biologically producednucleic acid include a recombinant nucleic acid produced (i.e.,replicated) in a living cell, such as a recombinant DNA vectorreplicated in bacteria or recombinant RNA or RNA vectors replicated inviruses (see for example, Sambrook et al., 2001, incorporated herein byreference).

Recombinant methods for producing nucleic acids in a cell are well knownto those of skill in the art. These include the use of vectors (viraland non-viral), plasmids, cosmids, and other vehicles for delivering anucleic acid to a cell, which may be the target cell (e.g., a cancercell) or simply a host cell (to produce large quantities of the desiredRNA molecule). Alternatively, such vehicles can be used in the contextof a cell free system so long as the reagents for generating the RNAmolecule are present. Such methods include those described in Sambrook,2003, Sambrook, 2001 and Sambrook, 1989, which are hereby incorporatedby reference.

In certain embodiments, the present invention concerns nucleic acidmolecules that are not synthetic. In some embodiments, the nucleic acidmolecule has a chemical structure of a naturally occurring nucleic acidand a sequence of a naturally occurring nucleic acid, such as the exactand entire sequence of a single stranded primary miRNA (see Lee, 2002),a single-stranded precursor miRNA, or a single-stranded mature miRNA.

II. Therapeutic Methods

Certain embodiments concern nucleic acids that perform the activities ofendogenous miR-124 when introduced into cells. In certain aspects,therapeutic nucleic acids (also referred to as nucleic acids) can besynthetic, non-synthetic, or a combination of synthetic andnon-synthetic miRNA sequences. Embodiments concern, in certain aspects,short nucleic acid molecules (therapeutic nucleic acids) that functionas miR-124. The nucleic acid molecules are typically synthetic. The term“synthetic” refers to a nucleic acid molecule that is chemicallysynthesized by a machine or apparatus and not produced naturally in acell.

In certain aspects, RNA molecules may not have an entire sequence thatis identical or complementary to a sequence of a naturally-occurringmature miRNA. Such molecules may encompass all or part of anaturally-occurring sequence or a complement thereof. For example, asynthetic nucleic acid may have a sequence that differs from thesequence of a mature miRNA, but that altered sequence may provide one ormore functions that can be achieved with the natural sequence.

The term “isolated” means that the nucleic acid molecules are initiallyseparated from different molecules (in terms of sequence or structure)and unwanted nucleic acid molecules such that a population of isolatednucleic acids is at least about 90% homogenous, and may be at leastabout 95, 96, 97, 98, 99, or 100% homogenous with respect to otherpolynucleotide molecules. In many aspects of the invention, a nucleicacid is isolated by virtue of it having been synthesized in vitroseparate from endogenous nucleic acids in a cell. It will be understood,however, that isolated nucleic acids may be subsequently mixed or pooledtogether.

In certain methods, there is a further step of administering theselected miRNA mimic or RNA molecule to a cell, tissue, organ, ororganism (collectively “biological matter”) in need of treatment relatedto modulation of the targeted miRNA or in need of the physiological orbiological results discussed herein (such as with respect to aparticular cellular pathway or result like decrease in cell viability).Consequently, in some methods there is a step of identifying a patientin need of treatment that can be provided by the miRNA mimic(s). It iscontemplated that an effective amount of an miRNA mimic can beadministered in some embodiments. In particular embodiments, there is atherapeutic benefit conferred on the biological matter, where a“therapeutic benefit” refers to an improvement in the one or moreconditions or symptoms associated with a disease or condition or animprovement in the prognosis, duration, or status with respect to thedisease. It is contemplated that a therapeutic benefit includes, but isnot limited to, a decrease in pain, a decrease in morbidity, a decreasein a symptom. For example, with respect to cancer, it is contemplatedthat a therapeutic benefit can be inhibition of tumor growth, preventionof metastasis, reduction in number of metastases, inhibition of cancercell proliferation, inhibition of cancer cell proliferation, inductionof cell death in cancer cells, inhibition of angiogenesis near cancercells, induction of apoptosis of cancer cells, reduction in pain,reduction in risk of recurrence, induction of chemo- or radiosensitivityin cancer cells, prolongation of life, and/or delay of death directly orindirectly related to cancer.

In certain embodiments, an miRNA mimic is used to treat cancer. Cancerincludes, but is not limited to, malignant cancers, tumors, metastaticcancers, unresectable cancers, chemo- and/or radiation-resistantcancers, and terminal cancers.

Cancers that may be evaluated, diagnosed, and/or treated by methods andcompositions of the invention include cancer cells from the bladder,blood, bone, bone marrow, brain, breast, cardiovascular system, cervix,colon, connective tissue, endometrium, epithelium, esophagus, fat,gastrointestine, glands, gum, head, kidney, liver, lung, meninges,muscle, nasopharynx, neck, neurons, ovary, pancreas, prostate, rectum,retina, skin, spleen, stomach, testis, thymus, thyroid, tongue, oruterus. In addition, the cancer may specifically be of the followinghistological type, though it is not limited to these: neoplasm,malignant; carcinoma; carcinoma, undifferentiated; giant and spindlecell carcinoma; small cell carcinoma; papillary carcinoma; squamous cellcarcinoma; lymphoepithelial carcinoma; basal cell carcinoma; pilomatrixcarcinoma; transitional cell carcinoma; papillary transitional cellcarcinoma; adenocarcinoma; gastrinoma, malignant; cholangiocarcinoma;hepatocellular carcinoma; combined hepatocellular carcinoma andcholangiocarcinoma; trabecular adenocarcinoma; adenoid cystic carcinoma;adenocarcinoma in adenomatous polyp; adenocarcinoma, familial polyposiscoli; solid carcinoma; carcinoid tumor, malignant; branchiolo-alveolaradenocarcinoma; papillary adenocarcinoma; chromophobe carcinoma;acidophil carcinoma; oxyphilic adenocarcinoma; basophil carcinoma; clearcell adenocarcinoma; granular cell carcinoma; follicular adenocarcinoma;papillary and follicular adenocarcinoma; nonencapsulating sclerosingcarcinoma; adrenal cortical carcinoma; endometroid carcinoma; skinappendage carcinoma; apocrine adenocarcinoma; sebaceous adenocarcinoma;ceruminous adenocarcinoma; mucoepidermoid carcinoma; cystadenocarcinoma;papillary cystadenocarcinoma; papillary serous cystadenocarcinoma;mucinous cystadenocarcinoma; mucinous adenocarcinoma; signet ring cellcarcinoma; infiltrating duct carcinoma; medullary carcinoma; lobularcarcinoma; inflammatory carcinoma; paget's disease, mammary; acinar cellcarcinoma; adenosquamous carcinoma; adenocarcinoma w/squamousmetaplasia; thymoma, malignant; ovarian stromal tumor, malignant;thecoma, malignant; granulosa cell tumor, malignant; androblastoma,malignant; sertoli cell carcinoma; leydig cell tumor, malignant; lipidcell tumor, malignant; paraganglioma, malignant; extra-mammaryparaganglioma, malignant; pheochromocytoma; glomangiosarcoma; malignantmelanoma; amelanotic melanoma; superficial spreading melanoma; maligmelanoma in giant pigmented nevus; epithelioid cell melanoma; bluenevus, malignant; sarcoma; fibrosarcoma; fibrous histiocytoma,malignant; myxosarcoma; liposarcoma; leiomyosarcoma; rhabdomyosarcoma;embryonal rhabdomyosarcoma; alveolar rhabdomyosarcoma; stromal sarcoma;mixed tumor, malignant; mullerian mixed tumor; nephroblastoma;hepatoblastoma; carcinosarcoma; mesenchymoma, malignant; brenner tumor,malignant; phyllodes tumor, malignant; synovial sarcoma; mesothelioma,malignant; dysgerminoma; embryonal carcinoma; teratoma, malignant;struma ovarii, malignant; choriocarcinoma; mesonephroma, malignant;hemangiosarcoma; hemangioendothelioma, malignant; kaposi's sarcoma;hemangiopericytoma, malignant; lymphangiosarcoma; osteosarcoma;juxtacortical osteosarcoma; chondrosarcoma; chondroblastoma, malignant;mesenchymal chondrosarcoma; giant cell tumor of bone; ewing's sarcoma;odontogenic tumor, malignant; ameloblastic odontosarcoma; ameloblastoma,malignant; ameloblastic fibrosarcoma; pinealoma, malignant; chordoma;glioma, malignant; ependymoma; astrocytoma; protoplasmic astrocytoma;fibrillary astrocytoma; astroblastoma; glioblastoma; oligodendroglioma;oligodendroblastoma; primitive neuroectodermal; cerebellar sarcoma;ganglioneuroblastoma; neuroblastoma; retinoblastoma; olfactoryneurogenic tumor; meningioma, malignant; neurofibrosarcoma;neurilemmoma, malignant; granular cell tumor, malignant; malignantlymphoma; Hodgkin's disease; Hodgkin's lymphoma; paragranuloma;malignant lymphoma, small lymphocytic; malignant lymphoma, large cell,diffuse; malignant lymphoma, follicular; mycosis fungoides; otherspecified non-Hodgkin's lymphomas; malignant histiocytosis; multiplemyeloma; mast cell sarcoma; immunoproliferative small intestinaldisease; leukemia; lymphoid leukemia; plasma cell leukemia;erythroleukemia; lymphosarcoma cell leukemia; myeloid leukemia;basophilic leukemia; eosinophilic leukemia; monocytic leukemia; mastcell leukemia; megakaryoblastic leukemia; myeloid sarcoma; and hairycell leukemia. Moreover, miRNA mimics can be used for precancerouscells, such as those cells in metaplasia, dysplasia, and hyperplasia.

Methods include supplying or enhancing the activity of one or moremiRNAs in a cell. Methods also concern inducing certain cellularcharacteristics by providing to a cell a particular nucleic acid, suchas a specific therapeutic nucleic acid molecule, i.e., a miRNA mimicmolecule. The therapeutic miRNA mimic may have a sequence that isidentical to a naturally occurring miRNA with one or more designmodifications.

In certain aspects, a particular nucleic acid molecule provided to thecell is understood to correspond to a particular miRNA in the cell, andthus, the miRNA in the cell is referred to as the “corresponding miRNA.”In situations in which a named miRNA molecule is introduced into a cell,the corresponding miRNA will be understood to provide miRNA function. Itis contemplated, however, that the therapeutic nucleic acid introducedinto a cell is not a mature miRNA but is capable of becoming orfunctioning as a mature miRNA under the appropriate physiologicalconditions. In cases in which a particular corresponding gene or genetranscript is being targeted by an miRNA mimic, the particular gene orgene transcript will be referred to as the “targeted gene.” It iscontemplated that multiple corresponding genes may be targeted by one ormore different miRNA mimics. In particular embodiments, more than onetherapeutic nucleic acid is introduced into a cell. Moreover, in otherembodiments, more than one miRNA mimic is introduced into a cell.Furthermore, a combination of therapeutic nucleic acid(s) may beintroduced into a cell. The inventors contemplate that a combination oftherapeutic nucleic acids may act at one or more points in cellularpathways of cells and that such combination may have increased efficacyon the target cell while not adversely affecting normal or non-targetedcells. Thus, a combination of therapeutic nucleic acids may have aminimal adverse effect on a subject or patient while supplying asufficient therapeutic effect, such as amelioration of a condition,growth inhibition of a cell, death of a targeted cell, alteration ofcell phenotype or physiology, slowing of cellular growth, sensitizationto a second therapy, sensitization to a particular therapy, and thelike.

Methods include identifying a cell or patient in need of inducing thosetherapeutics effects or cellular characteristics. Also, it will beunderstood that an amount of a therapeutic nucleic acid that is providedto a cell or organism is an “effective amount,” which refers to anamount needed (or a sufficient amount) to achieve a desired goal, suchas inducing a particular therapeutic effect or cellularcharacteristic(s) or reducing cancer growth or killing cancer cells oralleviating symptoms associated with a cancer.

In certain aspects methods can include providing or introducing into acell a nucleic acid molecule corresponding to a mature miRNA in the cellin an amount effective to achieve a desired physiological result.Moreover, methods can involve providing multiple synthetic therapeuticnucleic acids. It is contemplated that in these embodiments, methods mayor may not be limited to providing only one or more synthetic molecules.In this situation, a cell or cells may be provided with a syntheticmolecule corresponding to a particular miRNA and a synthetic moleculecorresponding to a different miRNA. Furthermore, any method articulatedusing a list of miRNA targets using Markush group language may bearticulated without the Markush group language and a disjunctive article(i.e., or) instead, and vice versa.

In some embodiments, there is a method for reducing or inhibiting cellproliferation, propagation, or renewal in a cell comprising introducinginto or providing to the cell an effective amount of (i) a therapeuticnucleic acid or (ii) a synthetic molecule that corresponds to a miRNAsequence. In certain embodiments the methods involve introducing intothe cell an effective amount of (i) a miRNA mimic molecule having a 5′to 3′ sequence that is at least 90% identical to the 5′ to 3′ sequenceof one or more mature miRNA.

Certain aspects of the invention include methods of treating apathologic condition, such as cancer or precancerous conditions. In oneaspect, the method comprises contacting a target cell with one or morenucleic acids comprising at least one nucleic acid segment having all ora portion of a miRNA sequence or a complement thereof. The segment maybe 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 30 or more nucleotides or nucleotide analog, including allintegers there between. An aspect of the invention includes themodulation of gene expression, miRNA expression or function or mRNAexpression or function within a target cell, such as a prostate cancercell or cancer stem cell (CSC).

Typically, an endogenous gene, miRNA or mRNA is modulated in the cell.In certain aspects, a therapeutic nucleic acid sequence comprises atleast one segment that is at least 70, 75, 80, 85, 90, 95, or 100%identical in nucleic acid sequence to one or more miRNA or gene sequenceor complement thereof. Modulation of the expression or processing of agene, miRNA, or mRNA of the cell or a virus can be through modulation ofthe processing of a nucleic acid, such processing includingtranscription, transportation and/or translation within a cell.Modulation may also be effected by the inhibition or enhancement ofmiRNA activity with a cell, tissue, or organ. Such processing may affectthe expression of an encoded product or the stability of the mRNA.

It will be understood in methods of the invention that a cell or otherbiological matter such as an organism (including patients) can beprovided a therapeutic nucleic acid corresponding to or targeting aparticular miRNA by administering to the cell or organism a nucleic acidmolecule that functions as the corresponding miRNA once inside the cell.Thus, it is contemplated that a nucleic acid is provided such that itbecomes processed into a mature and active miRNA once it has access tothe cell's processing machinery. In certain aspects, it is specificallycontemplated that the miRNA molecule provided is not a mature moleculebut a nucleic acid molecule that can be processed into the mature miRNAor its functional equivalent once it is accessible to processingmachinery.

The term “non-synthetic” in the context of miRNA means that the miRNA isnot “synthetic,” as defined herein. Furthermore, it is contemplated thatin embodiments of the invention that concern the use of syntheticmiRNAs, the use of corresponding non-synthetic miRNAs is also consideredan aspect of the invention, and vice versa. It will be understood thatthe term “providing” an agent is used to include “administering” theagent to a patient.

In certain embodiments, methods also include targeting an miRNA in acell or organism. The term “corresponding to a miRNA” means a nucleicacid will be employed so as to mimic (provide the activity or functionof) a selected miRNA.

Furthermore, it is contemplated that the nucleic acid compositions maybe provided as part of a therapy to a patient, in conjunction withtraditional therapies or preventative agents. Moreover, it iscontemplated that any method discussed in the context of therapy may beapplied as preventatively, particularly in a patient identified to bepotentially in need of the therapy or at risk of the condition ordisease for which a therapy is needed.

In addition, methods of the invention concern employing one or morenucleic acid corresponding to a miRNA and a therapeutic drug. Thenucleic acid can enhance the effect or efficacy of the drug, reduce anyside effects or toxicity, modify its bioavailability, and/or decreasethe dosage or frequency needed. In certain embodiments, the therapeuticdrug is a cancer therapeutic. Consequently, in some embodiments, thereis a method of treating a precancer or cancer in a patient comprisingadministering to the patient a cancer therapeutic (i.e., a secondtherapeutic) and an effective amount of at least one nucleic acidmolecule that improves the efficacy of the cancer therapeutic orprotects non-cancer cells. Cancer therapies also include a variety ofcombination therapies with both chemical and radiation based treatments.

Generally, miRNA mimics can be given to decrease the activity of anucleic acid targeted by the miRNA. Methods generally contemplatedinclude providing or introducing one or more different nucleic acidmolecules corresponding to one or more different genes. It iscontemplated that the following, at least the following, or at most thefollowing number of different nucleic acid or miRNA molecules may bedetected, assessed, provided or introduced: 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81,82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99,100, or more, including any value or range derivable there between.

III. Pharmaceutical Formulations and Delivery

Methods include the delivery of an effective amount of a therapeuticnucleic acid comprising or consisting essentially of a mature miRNAsequence. An “effective amount” of the pharmaceutical composition,generally, is defined as that amount sufficient to detectably andrepeatedly to achieve the stated desired result, for example, toameliorate, reduce, minimize or limit the extent of the disease or itssymptoms. Other more rigorous definitions may apply, includingelimination, eradication or cure of disease.

In certain embodiments, it is desired to kill cells, inhibit cellgrowth, inhibit metastasis, decrease tumor or tissue size, and/orreverse or reduce the malignant or disease phenotype of cells. Theroutes of administration will vary, naturally, with the location andnature of the lesion or site to be targeted, and include, e.g.,intradermal, subcutaneous, regional, parenteral, intravenous,intramuscular, intranasal, systemic, and oral administration andformulation. Injection or perfusion of a therapeutic nucleic acid isspecifically contemplated for discrete, solid, accessible precancers orcancers, or other accessible target areas. Local, regional, or systemicadministration also may be appropriate.

In the case of surgical intervention, the present invention may be usedpreoperatively, to render an inoperable lesion subject to resection.Alternatively, the present invention may be used at the time of surgery,and/or thereafter, to treat residual or metastatic disease. For example,a resected tumor bed may be injected or perfused with a formulationcomprising a therapeutic nucleic acid or combinations thereof.Administration may be continued post-resection, for example, by leavinga catheter implanted at the site of the surgery. Periodic post-surgicaltreatment also is envisioned. Continuous perfusion of a nucleic acidalso is contemplated.

Continuous administration also may be applied where appropriate, forexample, where a tumor or other undesired affected area is excised andthe tumor bed or targeted site is treated to eliminate residual,microscopic disease. Delivery via syringe or catherization iscontemplated. Such continuous perfusion may take place for a period fromabout 1-2 hours, to about 2-6 hours, to about 6-12 hours, to about 12-24hours, to about 1-2 days, to about 1-2 wk or longer following theinitiation of treatment. Generally, the dose of the therapeuticcomposition via continuous perfusion will be equivalent to that given bya single or multiple injections, adjusted over a period of time duringwhich the perfusion occurs.

Treatment regimens may vary as well and often depend on the type and/orlocation of a lesion, the target site, disease progression, and thehealth, immune condition, and age of the patient. Certain tumor typeswill require more aggressive treatment. The clinician will be bestsuited to make such decisions based on the known efficacy and toxicity(if any) of the therapeutic formulations.

In certain embodiments, the lesion or affected area being treated maynot, at least initially, be resectable. Treatments with compositions ofthe invention may increase the resectability of the lesion due toshrinkage at the margins or by elimination of certain particularlyinvasive portions. Following treatments, resection may be possible.Additional treatments subsequent to resection may serve to eliminatemicroscopic residual disease at the tumor or targeted site.

Treatments may include various “unit doses.” A unit dose is defined ascontaining a predetermined quantity of a therapeutic composition(s). Thequantity to be administered, and the particular route and formulation,are within the skill of those in the clinical arts. A unit dose need notbe administered as a single injection but may comprise continuousinfusion over a set period of time. A unit dose may conveniently bedescribed in terms of ng, or mg of miRNA or miRNA mimic. Alternatively,the amount specified may be the amount administered as the averagedaily, average weekly, or average monthly dose.

A therapeutic nucleic acid can be administered to the patient in a doseor doses of about or of at least about 0.5, 1, 5, 10, 15, 20, 25, 30,35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170,180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310,320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450,460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590,600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730,740, 750, 760, 770, 780, 790, 800, 810, 820, 830, 840, 850, 860, 870,880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990, 1000 ng, μgor mg, or more, or any range derivable therein. Alternatively, theamount specified may be the amount administered as the average daily,average weekly, or average monthly dose, or it may be expressed in termsof mg/kg, where kg refers to the weight of the patient and the mg isspecified above. In other embodiments, the amount specified is anynumber discussed above but expressed as mg/m² (with respect to tumorsize or patient surface area). In some embodiments, a dose or regimenmay be administered every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24 hours, and/or 1, 2, 3, 4, 5, 6, 7day(s), and/or 1, 2, 3, 4 weeks, and any range derivable therein, to apatient in need of treatment.

In some embodiments, the method for the delivery of a therapeuticnucleic acid is via local or systemic administration. However, thepharmaceutical compositions disclosed herein may also be administeredparenterally, subcutaneously, intratracheally, intravenously,intradermally, intramuscularly, or even intraperitoneally as describedin U.S. Pat. Nos. 5,543,158; 5,641,515 and 5,399,363 (each specificallyincorporated herein by reference in its entirety).

Injection of nucleic acids may be delivered by syringe or any othermethod used for injection of a solution, as long as the nucleic acid andany associated components can pass through the particular gauge ofneedle required for injection. A syringe system has also been describedfor use in gene therapy that permits multiple injections ofpredetermined quantities of a solution precisely at any depth (U.S. Pat.No. 5,846,225).

Solutions of the active compounds as free base or pharmacologicallyacceptable salts may be prepared in water suitably mixed with asurfactant, such as hydroxypropylcellulose. Dispersions may also beprepared in glycerol, liquid polyethylene glycols, mixtures thereof, andin oils. Under ordinary conditions of storage and use, thesepreparations contain a preservative to prevent the growth ofmicroorganisms. The pharmaceutical forms suitable for injectable useinclude sterile aqueous solutions or dispersions and sterile powders forthe extemporaneous preparation of sterile injectable solutions ordispersions (U.S. Pat. No. 5,466,468, specifically incorporated hereinby reference in its entirety). Typically, the form must be sterile andmust be fluid to the extent that easy syringability exists. It must bestable under the conditions of manufacture and storage and preservedagainst the contaminating action of microorganisms, such as bacteria andfungi. The carrier can be a solvent or dispersion medium containing, forexample, water, ethanol, polyol (e.g., glycerol, propylene glycol, andliquid polyethylene glycol, and the like), suitable mixtures thereof,and/or vegetable oils. Proper fluidity may be maintained, for example,by the use of a coating, such as lecithin, by the maintenance of therequired particle size in the case of dispersion and by the use ofsurfactants. The prevention of the action of microorganisms can bebrought about by various antibacterial and antifungal agents, forexample, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, andthe like. In many cases, it will be preferable to include isotonicagents, for example, sugars or sodium chloride. Prolonged absorption ofthe injectable compositions can be brought about by the use in thecompositions of agents delaying absorption, for example, aluminummonostearate and gelatin.

In certain formulations, a water-based formulation is employed while inothers, it may be lipid-based. In particular embodiments of theinvention, a composition comprising a nucleic acid of the invention isin a water-based formulation. In other embodiments, the formulation islipid based.

For parenteral administration in an aqueous solution, for example, thesolution should be suitably buffered if necessary and the liquid diluentfirst rendered isotonic with sufficient saline or glucose. Theseparticular aqueous solutions are especially suitable for intravenous,intramuscular, subcutaneous, intratumoral, intralesional, andintraperitoneal administration. In this connection, sterile aqueousmedia which can be employed will be known to those of skill in the artin light of the present disclosure. For example, one dosage may bedissolved in 1 ml of isotonic NaCl solution and either added to 1000 mlof hypodermoclysis fluid or injected at the proposed site of infusion,(see for example, “Remington's Pharmaceutical Sciences” 15th Edition,pages 1035-1038 and 1570-1580). Some variation in dosage willnecessarily occur depending on the condition of the subject beingtreated. The person responsible for administration will, in any event,determine the appropriate dose for the individual subject. Moreover, forhuman administration, preparations should meet sterility, pyrogenicity,general safety and purity standards as required by FDA Office ofBiologics standards. As used herein, a “carrier” includes any and allsolvents, dispersion media, vehicles, coatings, diluents, antibacterialand antifungal agents, isotonic and absorption delaying agents, buffers,carrier solutions, suspensions, colloids, and the like. The use of suchmedia and agents for pharmaceutical active substances is well known inthe art. Except insofar as any conventional media or agent isincompatible with the active ingredient, its use in the therapeuticcompositions is contemplated. Supplementary active ingredients can alsobe incorporated into the compositions. The phrase “pharmaceuticallyacceptable” refers to molecular entities and compositions that do notproduce an allergic or similar untoward reaction when administered to ahuman. The nucleic acid(s) are administered in a manner compatible withthe dosage formulation, and in such amount as will be therapeuticallyeffective. The quantity to be administered depends on the subject to betreated, including, e.g., the aggressiveness of the disease or cancer,the size of any tumor(s) or lesions, the previous or other courses oftreatment. Precise amounts of active ingredient required to beadministered depend on the judgment of the practitioner. Suitableregimes for initial administration and subsequent administration arealso variable, but are typified by an initial administration followed byother administrations. Such administration may be systemic, as a singledose, continuous over a period of time spanning 10, 20, 30, 40, 50, 60minutes, and/or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24 or more hours, and/or 1, 2, 3, 4, 5, 6,7, days or more. Moreover, administration may be through a time releaseor sustained release mechanism, implemented by formulation and/or modeof administration. Other delivery systems suitable include, but are notlimited to, time-release, delayed release, sustained release, orcontrolled release delivery systems. Such systems may avoid repeatedadministrations in many cases, increasing convenience to the subject andthe physician. Many types of release delivery systems are available andknown to those of ordinary skill in the art. They include, for example,polymer-based systems such as polylactic and/or polyglycolic acids,polyanhydrides, polycaprolactones, copolyoxalates, polyesteramides,polyorthoesters, polyhydroxybutyric acid, and/or combinations of these.Microcapsules of the foregoing polymers containing nucleic acids aredescribed in, for example, U.S. Pat. No. 5,075,109. Other examplesinclude nonpolymer systems that are lipid-based including sterols suchas cholesterol, cholesterol esters, and fatty acids or neutral fats suchas mono-, di- and triglycerides; hydrogel release systems;liposome-based systems; phospholipid based-systems; silastic systems;peptide based systems; wax coatings; compressed tablets usingconventional binders and excipients; or partially fused implants.Specific examples include, but are not limited to, erosional systems inwhich the RNA molecule is contained in a formulation within a matrix(for example, as described in U.S. Pat. Nos. 4,452,775, 4,675,189,5,736,152, 4,667,013, 4,748,034 and 5,239,660, which are herebyincorporated by reference), or diffusional systems in which an activecomponent controls the release rate (for example, as described in U.S.Pat. Nos. 3,832,253, 3,854,480, 5,133,974 and 5,407,686, which arehereby incorporated by reference). The formulation may be as, forexample, microspheres, hydrogels, polymeric reservoirs, cholesterolmatrices, or polymeric systems. In some embodiments, the system mayallow sustained or controlled release of the composition to occur, forexample, through control of the diffusion or erosion/degradation rate ofthe formulation containing the RNA molecules. In addition, a pump-basedhardware delivery system may be used to deliver one or more embodiments.Examples of systems in which release occurs in bursts includes, e.g.,systems in which the composition is entrapped in liposomes which areencapsulated in a polymer matrix, the liposomes being sensitive tospecific stimuli, e.g., temperature, pH, light or a degrading enzyme andsystems in which the composition is encapsulated by an ionically-coatedmicrocapsule with a microcapsule core degrading enzyme. Examples ofsystems in which release of the molecule is gradual and continuousinclude, e.g., erosional systems in which the composition is containedin a form within a matrix and effusional systems in which thecomposition permeates at a controlled rate, e.g., through a polymer.Such sustained release systems can be e.g., in the form of pellets, orcapsules. Compositions and methods can be used to enhance delivery ofRNA molecules (see Shim and Kwon (2010), which is incorporated herein byreference, for review). Compositions and methods for enhanced deliverycan provide for efficient delivery through the circulation, appropriatebiodistribution, efficient cellular transport, efficient intracellularprocessing, and the like. Formulations and compositions can include, butare not limited to one or more of chemical modification of RNAmolecules, incorporation of an RNA molecule or RNA precursors into aviral or non-viral vector, targeting of RNA molecule delivery, and/orcoupling RNA molecules with a cellular delivery enhancer.

In certain aspects chemically modified RNA molecules can include, withor without the chemical modifications discussed above, the conjugationof an RNA molecule to a carrier molecule. In certain aspects the carriermolecule is a natural or synthetic polymer. For example, a carriermolecule can be cholesterol or an RNA aptamer and the like. A carriermolecule can be conjugated to the RNA molecules at the 5′ and/or 3′ endof either the active or passenger strand, or at an internal nucleotideposition. The carrier can be conjugated the either strand of an RNAmolecules.

In a further aspect one or two strands of the RNA molecule can beencoded by or delivered with a viral vector. A variety of viral vectorsknow in the art can be modified to express or carry an RNA molecule in atarget cell, for example herpes simplex virus-1 or lentiviral vectorshave been used to enhance the delivery of siRNA.

In a still further aspect, an RNA molecule can be associated with anon-viral vector. Non-viral vectors can be coupled to targeting anddelivery enhancing moieties, such as antibodies, various polymers (e.g.,PEG), fusogenic peptides, linkers, cell penetrating peptides and thelike. Non-viral vectors include, but are not limited to liposomes andlipoplexes, polymers and peptides, synthetic particles and the like. Incertain aspects a liposome or lipoplex has a neutral, negative orpositive charge and can comprise cardolipin, anisamide-conjugatedpolyethylene glycol, dioleoyl phosphatidylcholine, or a variety of otherneutral, anionic, or cationic lipids or lipid conjugates. siRNAs can becomplexed to cationic polymers (e.g., polyethylenimine (PEI)),biodegradable cationic polysaccharide (e.g., chitosan), or cationicpolypeptides (e.g., atelocollagen, poly lysine, and protamine).

In certain aspects RNA delivery can be enhanced by targeting the RNA toa cell. Targeting moieties can be conjugated to a variety of deliverycompositions and provide selective or specific binding to a targetcell(s). Targeting moieties can include, but are not limited to moietiesthat bind to cell surface receptors, cell specific extracellularpolypeptide, saccharides or lipids, and the like. For example, smallmolecules such as folate, peptides such as RGD containing peptides, andantibodies such as antibodies to epidermal growth factor receptor can beused to target specific cell types.

In a further aspect, delivery can be enhanced by moieties that interactwith cellular mechanisms and machinery, such as uptake and intracellulartrafficking. In certain aspects cell penetrating peptides (CPPs) (e.g.,TAT and MPG from HIV-1, penetratin, polyarginine can be coupled with ansiRNA or a delivery vector to enhance delivery into a cell. Fusogenicpeptides (e.g., endodomain derivatives of HIV-1 envelope (HGP) orinfluenza fusogenic peptide (diINF-7)) can also be used to enhancecellular delivery.

A variety of delivery systems such as cholesterol-siRNA, RNAaptamers-siRNA, adenoviral vector, lentiviral vector, stable nucleicacid lipid particle (SNALP), cardiolipin analog-based liposome,DSPE-polyethylene glycol-DOTAP-cholesterol liposome, hyaluronan-DPPEliposome, neutral DOPC liposome, atelocollagen, chitosan,polyethylenimine, poly-lysine, protamine, RGD-polyethyleneglycol-polyethylenimine, HER-2 liposome with histidine-lysine peptide,HIV antibody-protamine, arginine, oligoarginine(9R) conjugated watersoluble lipopolymer (WSLP), oligoarginine (15R), TAT-PAMAM,cholesterol-MPG-8, DOPE-cationic liposome, GALA peptide-PEG-MMP-2cleavable peptide-DOPE and the like have been used to enhance thedelivery of siRNA.

The optimal therapeutic dose range for the miRNA mimics in cancerpatients is contemplated to be 0.01-5.0 mg of miRNA per kg of patientbody weight (mg/kg). In some embodiments, it is contemplated that about,at least about, or at most about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06,0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1,1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5,2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7. 3.8, 3.9,4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 mg of an RNAmolecule, or any range derivable therein, may be formulated in acomposition and/or administered to a patient. In some embodiments, apatient may be administered 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07,0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2,1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6,2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7. 3.8, 3.9, 4.0,4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 mg/kg of an RNAmolecule, or any range derivable therein, per dose or regimen, which maybe administered every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24 hours, and/or 1, 2, 3, 4, 5, 6, 7day(s), and/or 1, 2, 3, 4 weeks, and any range derivable therein.

Injections can be intravenous (IV), intraperitoneal (IP), intramuscular(IM), intratumoral (IT), intratracheally (for pulmonary delivery),intravitreal (for eye diseases), or subcutaneous, all of which have beendetermined to be effective as a delivery method for RNA moleculesdescribed herein. Several delivery technologies are specificallycontemplated, including, but not limited to, neutral lipid emulsion,(NLE), atelocollagen, SNALP, DiLA, and cyclodextrin, which are discussedin further detail below.

Neutral lipid emulsions (NLEs) are a collection of formulations thatcombine a neutral lipid, oil, and emulsifier with a miRNA mimic toproduce complexes that enable delivery of miRNAs to tumors and othertissues following intravenous (IV) injection. One such formulationcombines 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), squalene,Polysorbate 20 (Tween-20), and ascorbic acid at a ratio of1:2.6:53.4:0.1 (w/w). The NLE components are mixed in a solvent likechloroform and then the solvent is removed using a rotary evaporatorleaving a viscous solution. A miRNA mimic dissolved in PBS is added at aratio of 1:2 (w/w) to the DOPC. In certain embodiments, the ratio of RNAmolecule to DOPC is about, at least about, or at most about 0.1:1,0:2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1:0.9,1:0.8, 1:0.7, 1:0.6, 1:0.5, 1:0.4; 1:0.3, 1:0.2, 1:0.1 and any rangederivable therein. Sonication produces particles+miRNA that can be IVinjected at rates of approximately 0.01-1 mg/kg in humans. In certainembodiments, the amount of this formulation is provided to a patient inamounts of 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09,0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4,1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8,2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7. 3.8, 3.9, 4.0, 4.1, 4.2,4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 mg/kg to a patient per dose orregimen, which may be administered every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 hours, and/or 1,2, 3, 4, 5, 6, 7 day(s), and/or 1, 2, 3, 4 weeks, and any rangederivable therein.

Atelocollagen/miRNA complexes are prepared by mixing equal volumes ofatelocollagen (0.1% in PBS at pH 7.4) (Koken Co., Ltd.; Tokyo, Japan)and miRNA solution (20 μM miRNA) and rotating the mixtures for 1 hr at4° C. The resulting miRNA/atelocollagen complexes are diluted in PBS toa final concentration of atelocollagen of 0.05%. In certain embodiments,the final percentage concentration of atelocollagen is about, about atleast, or about at most 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%,0.08%, 0.09%, 0.10%, 0.11%, 0.10%, 0.11%, 0.12%, 0.13, 0.14%, 0.15%,0.16%, 0.17%, 0.18%, 0.19%, 0.20%, and any range derivable therein.

SNALP categorizes a collection of formulations developed by Tekmira forthe systemic delivery of nucleic acids. The most published formulationcontains the lipids 3-N-[(qmethoxypoly(ethyleneglycol)2000)carbamoyl]-1,2-dimyristyloxy-propylamine (PEG-C-DMA),1,2-dilinoleyloxy-N,N-dimethyl-3-aminopropane(DLinDMA),1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) andcholesterol, in a 2:40:10:48 molar percent ratio. The lipid formulationis mixed with siRNA/miRNA and forms particles using the ethanol dilutionmethod (Jeffs 2005, which is hereby incorporated by reference). In someembodiments, the ratio of lipid to nucleic acid (w:w) is, is at least,or is at most about 0.001:1, 0.002:1, 0.003:1, 0.004:1, 0.005:1,0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, 0.02:1, 0.03:1, 0.04:1,0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1,0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1:0.9, 1:0.8, 1:0.7, 1:0.6,1:0.5, 1:0.4; 1:0.3, 1:0.2, 1:0.1, 1:0.09, 1:0.08, 1:0.07, 1:0.06,1:0.05, 1:0.04, 1:0.03, 1:0.02, 1:0.01, 1:0.009, 1:0.008, 1:0.007,1:0.006, 1:0.005, 1:0.004, 1:0.003, 1:0.002, 1:0.001, or any rangederivable therein.

Tekmira claims to achieve greater than 90% encapsulation efficiency.Particle sizes are approximatelyl10 nm.

DiLA² describes a group of a variety of formulations developed by MarinaBiotech Inc. (Bothell, Wash., USA) for the systemic delivery of small,dsRNAs. One formulation combines C18:1-norArg-NH₃Cl—C16, cholesterylhemisuccinate (CHEMS, Anatrace, CH₂₁₀), cholesterol (Anatrace CH200),and DMPE-PEG2k (Genzyme) at ratios of 50:28:20:2 (w/w). A small, dsRNAis combined with the lipid formulation at an RNA:lipid ratio of between1.7:1 to 5:1 (w/w). In some embodiments, the RNA:lipid ratio is about,at least about, or at most about 0.001:1, 0.002:1, 0.003:1, 0.004:1,0.005:1, 0.006:1, 0.007:1, 0.008:1, 0.009:1, 0.01:1, 0.02:1, 0.03:1,0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.2:1, 0.3:1,0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1:0.9, 1:0.8, 1:0.7,1:0.6, 1:0.5, 1:0.4; 1:0.3, 1:0.2, 1:0.1, 1:0.09, 1:0.08, 1:0.07,1:0.06, 1:0.05, 1:0.04, 1:0.03, 1:0.02, 1:0.01, 1:0.009, 1:0.008,1:0.007, 1:0.006, 1:0.005, 1:0.004, 1:0.003, 1:0.002, 1:0.001, and anyrange derivable therein. The two components are mixed via an impingingstream and incubated for 1 hour to produce stable particles withdiameters of approximately 125 nm.

Pharmaceuticals, Inc. (Pasadena, Calif., USA) has developed a deliveryplatform called RONDEL™ that features cyclodextrin-based particles.Cyclodextrin polycations (CDP) are mixed with an adamantane-PEG5000(AD-PEG) conjugate at a 1:1 AD:CDP (mol/mol) ratio (Hu-Lieskovan 2005,which is hereby incorporated by reference). Transferrin-modified AD-PEG(AD-PEG-transferrin) can be added at a 1:1,000 AD-PEG-transferrin:AD-PEG(w/w) ratio to provide a targeting moiety to improve delivery to cancercells with elevated transferrin levels. The mixture is added to an equalvolume of RNA molecule at a charge ratio (positive charges from CDP tonegative charges from miRNA backbone) of 3:1 (+/−). In certainembodiments, the charge ratio between the mixture and RNA molecules isabout, at least about, or at most about 5:1, 4:1, 3:1, 2:1, 1:1, 1:2,1:3, 1:4, 1:5, or any range derivable therein, An equal volume of 10%(w/v) glucose in water is added to the resulting polyplexes to give afinal polyplex formulation in 5% (w/v) glucose (D5W) suitable forinjection.

In some embodiments, particles are used to delivery a therapeuticnucleic acid. In some embodiments, the particle size is about, at leastabout, or at most about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110,120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250 nm,or any range derivable therein.

A. Combination Treatments

In certain embodiments, the compositions and methods involve atherapeutic nucleic acid. These compositions can be used in combinationwith a second therapy to enhance the effect of the miRNA therapy, orincrease the therapeutic effect of another therapy being employed. Thesecompositions would be provided in a combined amount effective to achievethe desired effect, such as the killing of a cancer cell and/or theinhibition of cellular hyperproliferation. This process may involvecontacting the cells with the therapeutic nucleic acid or second therapyat the same or different time. This may be achieved by contacting thecell with one or more compositions or pharmacological formulation thatincludes one or more of the agents, or by contacting the cell with twoor more distinct compositions or formulations, wherein one compositionprovides (1) therapeutic nucleic acid; and/or (2) a second therapy. Asecond composition or method may be administered that includes achemotherapy, radiotherapy, surgical therapy, immunotherapy or genetherapy.

It is contemplated that one may provide a patient with the miRNA therapyand the second therapy within about 12-24 h of each other and, morepreferably, within about 6-12 h of each other. In some situations, itmay be desirable to extend the time period for treatment significantly,however, where several days (2, 3, 4, 5, 6 or 7) to several weeks (1, 2,3, 4, 5, 6, 7 or 8) lapse between the respective administrations.

In certain embodiments, a course of treatment will last 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90 days or more. It iscontemplated that one agent may be given on day 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80,81, 82, 83, 84, 85, 86, 87, 88, 89, and/or 90, any combination thereof,and another agent is given on day 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,85, 86, 87, 88, 89, and/or 90, or any combination thereof. Within asingle day (24-hour period), the patient may be given one or multipleadministrations of the agent(s). Moreover, after a course of treatment,it is contemplated that there is a period of time at which no treatmentis administered. This time period may last 1, 2, 3, 4, 5, 6, 7 days,and/or 1, 2, 3, 4, 5 weeks, and/or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12months or more, depending on the condition of the patient, such as theirprognosis, strength, health, etc.

Administration of any compound or therapy of the present invention to apatient will follow general protocols for the administration of suchcompounds, taking into account the toxicity, if any, of the vector orany protein or other agent. Therefore, in some embodiments there is astep of monitoring toxicity that is attributable to combination therapy.It is expected that the treatment cycles would be repeated as necessary.It also is contemplated that various standard therapies, as well assurgical intervention, may be applied in combination with the describedtherapy.

In specific aspects, it is contemplated that a second therapy, such aschemotherapy, radiotherapy, immunotherapy, surgical therapy or othergene therapy, is employed in combination with the miRNA therapy, asdescribed herein.

Examples of chemotherapeutic agents include alkylating agents such asthiotepa and cyclosphosphamide; alkyl sulfonates such as busulfan,improsulfan and piposulfan; aziridines such as benzodopa, carboquone,meturedopa, and uredopa; ethylenimines and methylamelamines includingaltretamine, triethylenemelamine, trietylenephosphoramide,triethiylenethiophosphoramide and trimethylolomelamine; acetogenins(especially bullatacin and bullatacinone); a camptothecin (including thesynthetic analogue topotecan); bryostatin; callystatin; CC-1065(including its adozelesin, carzelesin and bizelesin syntheticanalogues); cryptophycins (particularly cryptophycin 1 and cryptophycin8); dolastatin; duocarmycin (including the synthetic analogues, KW-2189and CB1-TM1); eleutherobin; pancratistatin; a sarcodictyin;spongistatin; nitrogen mustards such as chlorambucil, chlornaphazine,cholophosphamide, estramustine, ifosfamide, mechlorethamine,mechlorethamine oxide hydrochloride, melphalan, novembichin,phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureassuch as carmustine, chlorozotocin, fotemustine, lomustine, nimustine,and ranimnustine; antibiotics such as the enediyne antibiotics (e.g.,calicheamicin, especially calicheamicin gammall and calicheamicinomegaI1; dynemicin, including dynemicin A; bisphosphonates, such asclodronate; an esperamicin; as well as neocarzinostatin chromophore andrelated chromoprotein enediyne antiobiotic chromophores, aclacinomysins,actinomycin, authrarnycin, azaserine, bleomycins, cactinomycin,carabicin, caminomycin, carzinophilin, chromomycinis, dactinomycin,daunorubicin, detorubicin, 6-diazo-5-oxo-L-norleucine, doxorubicin(including morpholino-doxorubicin, cyanomorpholino-doxorubicin,2-pyrrolino-doxorubicin and deoxydoxorubicin), epirubicin, esorubicin,idarubicin, marcellomycin, mitomycins such as mitomycin C, mycophenolicacid, nogalarnycin, olivomycins, peplomycin, potfiromycin, puromycin,quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin,ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexateand 5-fluorouracil (5-FU); folic acid analogues such as denopterin,methotrexate, pteropterin, trimetrexate; purine analogs such asfludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidineanalogs such as ancitabine, azacitidine, 6-azauridine, carmofur,cytarabine, dideoxyuridine, doxifluridine, enocitabine, floxuridine;androgens such as calusterone, dromostanolone propionate, epitiostanol,mepitiostane, testolactone; anti-adrenals such as aminoglutethimide,mitotane, trilostane; folic acid replenisher such as frolinic acid;aceglatone; aldophosphamide glycoside; aminolevulinic acid; eniluracil;amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine;diaziquone; elformithine; elliptinium acetate; an epothilone; etoglucid;gallium nitrate; hydroxyurea; lentinan; lonidainine; maytansinoids suchas maytansine and ansamitocins; mitoguazone; mitoxantrone; mopidanmol;nitraerine; pentostatin; phenamet; pirarubicin; losoxantrone;podophyllinic acid; 2-ethylhydrazide; procarbazine; PSK polysaccharidecomplex); razoxane; rhizoxin; sizofuran; spirogermanium; tenuazonicacid; triaziquone; 2,2′,2″-trichlorotriethylamine; trichothecenes(especially T-2 toxin, verracurin A, roridin A and anguidine); urethan;vindesine; dacarbazine; mannomustine; mitobronitol; mitolactol;pipobroman; gacytosine; arabinoside (“Ara-C”); cyclophosphamide;thiotepa; taxoids, e.g., paclitaxel and doxetaxel; chlorambucil;gemcitabine; 6-thioguanine; mercaptopurine; methotrexate; platinumcoordination complexes such as cisplatin, oxaliplatin and carboplatin;vinblastine; platinum; etoposide (VP-16); ifosfamide; mitoxantrone;vincristine; vinorelbine; novantrone; teniposide; edatrexate;daunomycin; aminopterin; xeloda; ibandronate; irinotecan (e.g., CPT-11);topoisomerase inhibitor RFS 2000; difluoromethylornithine (DMFO);retinoids such as retinoic acid; capecitabine; and pharmaceuticallyacceptable salts, acids or derivatives of any of the above.

Radiotherapy, also called radiation therapy, is the treatment of cancerand other diseases with ionizing radiation. Ionizing radiation depositsenergy that injures or destroys cells in the area being treated bydamaging their genetic material, making it impossible for these cells tocontinue to grow. Although radiation damages both cancer cells andnormal cells, the latter are able to repair themselves and functionproperly. Radiotherapy may be used to treat localized solid tumors, suchas cancers of the skin, tongue, larynx, brain, breast, or cervix. It canalso be used to treat leukemia and lymphoma (cancers of theblood-forming cells and lymphatic system, respectively).

Radiation therapy used according to the present invention may include,but is not limited to, the use of γ-rays, X-rays, and/or the directeddelivery of radioisotopes to tumor cells. Other forms of DNA damagingfactors are also contemplated such as microwaves, proton beamirradiation (U.S. Pat. Nos. 5,760,395 and 4,870,287) and UV-irradiation.It is most likely that all of these factors effect a broad range ofdamage on DNA, on the precursors of DNA, on the replication and repairof DNA, and on the assembly and maintenance of chromosomes. Dosageranges for X-rays range from daily doses of 50 to 200 roentgens forprolonged periods of time (3 to 4 wk), to single doses of 2000 to 6000roentgens. Dosage ranges for radioisotopes vary widely, and depend onthe half-life of the isotope, the strength and type of radiationemitted, and the uptake by the neoplastic cells. Radiotherapy maycomprise the use of radiolabeled antibodies to deliver doses ofradiation directly to the cancer site (radioimmunotherapy). Onceinjected into the body, the antibodies actively seek out the cancercells, which are destroyed by the cell-killing (cytotoxic) action of theradiation. This approach can minimize the risk of radiation damage tohealthy cells.

Stereotactic radio-surgery (gamma knife) for brain and other tumors doesnot use a knife, but very precisely targeted beams of gamma radiotherapyfrom hundreds of different angles. Only one session of radiotherapy,taking about four to five hours, is needed. For this treatment aspecially made metal frame is attached to the head. Then, several scansand x-rays are carried out to find the precise area where the treatmentis needed. During the radiotherapy for brain tumors, the patient lieswith their head in a large helmet, which has hundreds of holes in it toallow the radiotherapy beams through. Related approaches permitpositioning for the treatment of tumors in other areas of the body.

In the context of cancer treatment, immunotherapeutics, generally, relyon the use of immune effector cells and molecules to target and destroycancer cells. Trastuzumab (Herceptin™) is such an example. The immuneeffector may be, for example, an antibody specific for some marker onthe surface of a tumor cell. The antibody alone may serve as an effectorof therapy or it may recruit other cells to actually affect cellkilling. The antibody also may be conjugated to a drug or toxin(chemotherapeutic, radionuclide, ricin A chain, cholera toxin, pertussistoxin, etc.) and serve merely as a targeting agent. Alternatively, theeffector may be a lymphocyte carrying a surface molecule that interacts,either directly or indirectly, with a tumor cell target. Variouseffector cells include cytotoxic T cells and NK cells. The combinationof therapeutic modalities, i.e., direct cytotoxic activity andinhibition or reduction of ErbB2 would provide therapeutic benefit inthe treatment of ErbB2 overexpressing cancers.

In one aspect of immunotherapy, the tumor or disease cell must bear somemarker that is amenable to targeting, i.e., is not present on themajority of other cells. Many tumor markers exist and any of these maybe suitable for targeting in the context of the present invention.Common tumor markers include carcinoembryonic antigen, prostate specificantigen, urinary tumor associated antigen, fetal antigen, tyrosinase(p97), gp68, TAG-72, HMFG, Sialyl Lewis Antigen, MucA, MucB, PLAP,estrogen receptor, laminin receptor, erb B and p155. An alternativeaspect of immunotherapy is to combine anticancer effects with immunestimulatory effects. Immune stimulating molecules also exist including:cytokines such as IL-2, IL-4, IL-12, GM-CSF, gamma-IFN, chemokines suchas MIP-1, MCP-1, IL-8 and growth factors such as FLT3 ligand. Combiningimmune stimulating molecules, either as proteins or by using genedelivery in combination with a tumor suppressor such as MDA-7 has beenshown to enhance anti-tumor effects (Ju et al., 2000). Moreover,antibodies against any of these compounds can be used to target theanti-cancer agents discussed herein.

Examples of immunotherapies currently under investigation or in use areimmune adjuvants e.g., Mycobacterium bovis, Plasmodium falciparum,dinitrochlorobenzene and aromatic compounds (U.S. Pat. Nos. 5,801,005and 5,739,169; Hui and Hashimoto, 1998; Christodoulides et al., 1998),cytokine therapy e.g., interferons α, β and γ; IL-1, GM-CSF and TNF(Bukowski et al., 1998; Davidson et al., 1998; Hellstrand et al., 1998)gene therapy e.g., TNF, IL-1, IL-2, p53 (Qin et al., 1998; Austin-Wardand Villaseca, 1998; U.S. Pat. Nos. 5,830,880 and 5,846,945) andmonoclonal antibodies e.g., anti-ganglioside GM2, anti-HER-2, anti-p185;Pietras et al., 1998; Hanibuchi et al., 1998; U.S. Pat. No. 5,824,311).Herceptin (trastuzumab) is a chimeric (mouse-human) monoclonal antibodythat blocks the HER2-neu receptor. It possesses anti-tumor activity andhas been approved for use in the treatment of malignant tumors (Dillman,1999). A non-limiting list of several known anti-cancerimmunotherapeutic agents and their targets includes (GenericName/Target) Cetuximab/EGFR, Panitumuma/EGFR, Trastuzumab/erbB2receptor, Bevacizumab/VEGF, Alemtuzumab/CD52, Gemtuzumabozogamicin/CD33, Rituximab/CD20, Tositumomab/CD20, Matuzumab/EGFR,Ibritumomab tiuxetan/CD20, Tositumomab/CD20, HuPAM4/MUC1,MORAb-009/Mesothelin, G250/carbonic anhydrase IX, mAb 8H9/8H9 antigen,M195/CD33, Ipilimumab/CTLA4, HuLuc63/CS1, Alemtuzumab/CD53,Epratuzumab/CD22, BC8/CD45, HuJ591/Prostate specific membrane antigen,hA20/CD20, Lexatumumab/TRAIL receptor-2, Pertuzumab/HER-2 receptor,Mik-beta-1/IL-2R, RAV12/RAAG12, SGN-30/CD30, AME-133v/CD20, HeFi-1/CD30,BMS-663513/CD137, Volociximab/anti-α5β1 integrin, GC1008/TGFIβ,HCD122/CD40, Siplizumab/CD2, MORAb-003/Folate receptor alpha, CNTO328/IL-6, MDX-060/CD30, Ofatumumab/CD20, and SGN-33/CD33. It iscontemplated that one or more of these therapies may be employed withthe miRNA therapies described herein.

A number of different approaches for passive immunotherapy of cancerexist. They may be broadly categorized into the following: injection ofantibodies alone; injection of antibodies coupled to toxins orchemotherapeutic agents; injection of antibodies coupled to radioactiveisotopes; injection of anti-idiotype antibodies; and finally, purging oftumor cells in bone marrow.

Approximately 60% of persons with cancer will undergo surgery of sometype, which includes preventative, diagnostic or staging, curative andpalliative surgery. Curative surgery is a cancer treatment that may beused in conjunction with other therapies, such as the treatment of thepresent invention, chemotherapy, radiotherapy, hormonal therapy, genetherapy, immunotherapy and/or alternative therapies.

Curative surgery includes resection in which all or part of canceroustissue is physically removed, excised, and/or destroyed. Tumor resectionrefers to physical removal of at least part of a tumor. In addition totumor resection, treatment by surgery includes laser surgery,cryosurgery, electrosurgery, and microscopically controlled surgery(Mohs' surgery). It is further contemplated that the present inventionmay be used in conjunction with removal of superficial cancers,precancers, or incidental amounts of normal tissue.

Upon excision of part of all of cancerous cells, tissue, or tumor, acavity may be formed in the body. Treatment may be accomplished byperfusion, direct injection or local application of the area with anadditional anti-cancer therapy. Such treatment may be repeated, forexample, every 1, 2, 3, 4, 5, 6, or 7 days, or every 1, 2, 3, 4, and 5weeks or every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months. Thesetreatments may be of varying dosages as well.

Hormonal therapy may also be used in conjunction with the presentinvention or in combination with any other cancer therapy previouslydescribed. The use of hormones may be employed in the treatment ofcertain cancers such as breast, prostate, ovarian, or cervical cancer tolower the level or block the effects of certain hormones such astestosterone or estrogen. This treatment is often used in combinationwith at least one other cancer therapy as a treatment option or toreduce the risk of metastases.

IV. Examples

The following examples are included to demonstrate preferred embodimentsof the invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples which follow representtechniques discovered by the inventor to function well in the practiceof the invention, and thus can be considered to constitute preferredmodes for its practice. However, those of skill in the art should, inlight of the present disclosure, appreciate that many changes can bemade in the specific embodiments which are disclosed and still obtain alike or similar result without departing from the spirit and scope ofthe invention.

Example 1 Effect of Nucleotide Modifications in Passenger or ActiveStrands Of miR-124 ON Anti-Cell Proliferation Activity

The activity of a miRNA depends on both its ability to interact withproteins of the RNA-Induced Silencing Complex (RISC) and its ability tointeract with an mRNA target through hybridization. To determine whichnucleotides in a double-stranded miR-124 could be modified withoutdisrupting miRNA activity within cells, we used a series ofdouble-stranded miR-124 mimics with 2′ oxygen-methyl (2′O-Me)-modifiednucleotides incorporated at two adjacent positions on the active strandor on the passenger strand of the double-stranded miRNA (Table 1). Inaddition to the 2′O-Me modifications, each passenger strand had a 5′-endmodification consisting of an amino C6 nucleotide (primary amine groupattached to a 6-carbon spacer) attached to the 5′ terminal PO₄ ⁻ group.

TABLE 1Sequence and modification patterns of miR-124 mimics. Nucleotide locations of2′O—Me—modified nucleotides are indicated as bold, italicized, and underlined.Position of 2′O—Me— 5′ Strand Sequence (SEQ ID NO:4)Modified Nucleotides Modification Passenger UGGCAUUCACCGCGUGCCUUAA None5′-amino C6 Passenger

1, 2 5′-amino C6 Passenger

3, 4 5′-amino C6 Passenger

5, 6 5′-amino C6 Passenger

7, 8 5′-amino C6 Passenger

9, 10 5′-amino C6 Passenger

11, 12 5′-amino C6 Passenger

13, 14 5′-amino C6 Passenger

15, 16 5′-amino C6 Passenger

17, 18 5′-amino C6 Passenger

19, 20 5′-amino C6 Passenger

1, 2, 21, 22 5′-amino C6 Passenger

1, 2, 3, 20, 21, 22 5′-amino C6 Passenger

2, 3, 6, 7, 10, 11, 14, 15, 18, 19 5′-amino C6 Passenger

4, 5, 8, 9, 12, 13, 16, 17, 20, 21 5′-amino C6 Position of 2′O—Me— 5′Strand Sequence (SEQ ID NO:2) Modified Nucleotides Modification ActiveUUAAGGCACGCGGUGAAUGCCA None None Active

1, 2 None Active

3, 4 None Active

5, 6 None Active

7, 8 None Active

9, 10 None Active

11, 12 None Active

13, 14 None Active

15, 16 None Active

17, 18 None Active

19, 20 None Active

1, 2, 21, 22 None Active

1, 2, 3, 20, 21, 22 None Active

2, 3, 6, 7, 10, 11, 14, 15, 18, 19 None Active

3, 4, 7, 8, 11, 12, 15, 16, 19, 20 None

The inventors examined the effects of the oligonucleotide modificationson the activities of the miR-124 mimics. Synthetic, passenger strandoligonucleotide having a 5′-amino C6 modification and no 2′O-Memodifications was annealed to each of the synthetic, modified activestrand oligonucleotides (Table 1). Synthetic, unmodified active strandoligonucleotide was annealed to each of the synthetic, modifiedpassenger strand oligonucleotides (Table 1.) The lung cancer cell line(H460) was reverse transfected with the resultant double strandedoligonucleotides or with a negative control miRNA (Life Technologies,Inc./Ambion, Inc; Austin, Tex., USA; cat. no. AM17103) at finalconcentrations of 30 nM. Cell lines were transiently transfected usingLipofectamine 2000 (Life Technologies, Inc./Invitrogen Corp., Carlsbad,Calif., USA) according to the manufacturer's recommendations using thefollowing parameters: 5,000 cells per well in a 96 well plate, 0.1-0.2μl of Lipofectamine 2000 (cell line specific optimized), in 100 μl totalvolume of media. Cell viability assays were performed using thealamarBlue® reagent (Invitrogen Corp.; Carlsbad, Calif., USA; cat. no.DAL1100) according to the manufacturer's protocol at days 3, 4, and 7following transfection. A fluorescent plate reader was used to measureaccumulation of resorufin (560 nm excitation, 590 nm emission) which isthe reduced substrate of alamarBlue®. Resorufin accumulation isindicative of the number of viable cells per well. The relative numberof proliferating cells for each cell population transfected with adouble-stranded miR-124 having 2′O-Me modifications was calculated bydividing the fluorescence of cells transfected with the unmodifiedmiR-124 mimic by the fluorescence of cells transfected with the2′O-Me-modified miR-124s and multiplying the result by 100. Relativeanti-proliferation values are shown in Table 2.

TABLE 2 Effect of 2′-O Me-modified nucleotides in miR- 124 onproliferation of H460 lung cancer cells. 2′O—Me-Modified PercentageAnti-Cell Nucleotide Positions Proliferation Activity Relative to SEQ IDModification Modification NO: 4 (passenger) or in Passenger in ActiveNO: 2 (active) Strand Strand 1, 2 111.31 27.75 3, 4 105.20 43.13 5, 699.32 94.45 7, 8 41.47 105.36  9, 10 35.86 60.84 11, 12 75.34 91.51 13,14 91.39 53.85 15, 16 90.69 48.46 17, 18 110.14 84.37 19, 20 89.81 66.281, 2, 21, 22 109.48 26.28 1, 2, 3, 20, 21, 22 119.92 25.91 Anti-cellproliferative activity of a synthetic, double-stranded miR-124 having no2′O—Me modifications was set at 100%. Percentage anti-cell proliferationvalues greater than 100 indicate anti-proliferative activity that ishigher than that of the unmodified miR-124 control. The indicatedmodifications were in the passenger strand or active strand only. Allpassenger strands had a 5′-amino C6 modification.

As shown in Table 2, 2′O-Me modifications in the passenger strand atpositions 1+2; 3+4; 17+18; 1+2+21+22; and 1+2+3+20+21+22 and in theactive strand at positions 7+8 resulted in increased anti-proliferativeactivity over that observed for the unmodified control miR-124. 2′O—Memodifications in the active strand at positions 1+2; 3+4; 9+10; 13+14;15+16; 19+20; 1+2+21+22; and 1+2+3+20+21+22 and in the passenger strandat 7+8; 9+10; and 11+12 resulted in substantially impairedanti-proliferative activity when compared to the miR-124 mimic having no2′O-Me modifications. 2′O-Me modifications at positions 5+6; 11+12; and17+18 of the active strand and at positions 5+6; 13+14; 15+16; and 19+20of the passenger strand had little detrimental effect onanti-proliferative activity.

Example 2 Effect of Combined Nucleotide Modifications in Passenger andActive Strands of miR-1240N Anti-Cell Proliferation Activity

The inventors evaluated the anti-cell proliferation activity of miR-124mimics having modified nucleotides in both the passenger and activestrands. Various modified passenger and active strand oligonucleotideswere annealed to form miR-124 mimics with modifications on both strands.Lung cancer (H460) and liver cancer (C3A) cell lines were reversetransfected with the various mimics as well as with a negative controlmiRNA (Ambion, cat. no. AM17103) at final concentrations of 30 nM.Lipofectamine 2000 (Invitrogen) was used according to the manufacturer'srecommendations using the following parameters: 5,000 cells per well ina 96 well plate, 0.1-0.2 μl of Lipofectamine 2000 (cell line optimized),in 100 μl total volume of media. An alamarBlue® assay (Invitrogen, cat.no. DAL1100) was performed on the cells according to the manufacturer'sprotocol, on day six following transfection. A fluorescent plate readerwas used to measure accumulation of resorufin (560 nm excitation, 590 nmemission) which is the reduced substrate in alamarBlue®. Resorufinfluorescence correlates with the number of viable cells per well. Therelative number of proliferating cells for each transfected cellpopulation was calculated by dividing the fluorescence of cellstransfected with the unmodified miR-124 mimic by the fluorescence ofcells transfected with the double-stranded 2′O-Me-modified miR-124mimics and multiplying the result by 100. Results are shown in Table 3.

TABLE 3 Effects of nucleotide modifications in a double-stranded miR-124mimic on anti-cell proliferation activity of lung cancer cells (H460)and liver cancer cells (C3A). Percentage Active Strand Passenger StrandAnti-Cell 2′O—Me-Modified 2′O—Me-Modified Proliferation NucleotidePositions Nucleotide Positions Activity None None 100 None 1, 2, 21,22125 None 1, 2, 3, 20, 21, 22 121 5, 6 None 98 5, 6 1, 2, 21, 22 113 5, 61, 2, 3, 20, 21, 22 106 7, 8 None 106 7, 8 1, 2, 21, 22 162 7, 8 1, 2,3, 20, 21, 22 256 17, 18 None 95 17, 18 1, 2, 21, 22 125 17, 18 1, 2, 3,20, 21, 22 134 1, 2, 3, 20, 21, 22 None 59 1, 2, 3, 20, 21, 22 1, 2, 21,22 57 1, 2, 3, 20, 21, 22 1, 2, 3, 20, 21, 22 59 Values for percentageof anti-cell proliferation activity that are greater than 100 indicateanti-proliferative activity that is higher with modified miR-124 mimicsthan that observed with unmodified miR-124. The indicated modificationswere in the passenger strand, active strand, or both strands. Allpassenger strands had a 5′-amino C6 modification.

As shown in Table 3 (involving an active strand with SEQ ID NO:2 and apassenger strand with SEQ ID NO:4), most miR-124 mimics having 2′O-Memodifications at positions 5,6; 7,8; or 17,18 in the active strand hadhigher anti-cell proliferation activity than did the unmodified miR-124mimic, regardless of the number of modification sin the passengerstrand. Several mimics having modifications in both active and passengerstrands have significantly greater anti-cell proliferation activitiesthan would be expected based upon data from mimics having only a singlemodified strand which suggests synergistic effects of the modifications.For instance, the 7+8 2′O-Me-modified active strand combined with the1+2+21+22 or with the 1+2+3+20+21+22 2′OMe-modified passenger strandsare considerably more anti-proliferative than mimics having only onemodified strand. Likewise, the 17+18 2′O-Me-modified active strand hassignificantly more activity than expected when combined with the1+2+3+20+21+22 2′O-Me-modified passenger strand. These data suggest that2′O-Me modifications not only enhance the anti-proliferative activitiesof miR-124 mimics but that certain combinations of modifications can beapplied to significantly enhance the activities of a miR-124 mimic.

Example 3 Nucleotide Modifications in Both Active and PassengenerStrands Contribute to Stability of miRNA Mimics

Because a 2′OH is required for ribonucleases to cleave RNA molecules,incorporating 2′-modified nucleotides into RNA molecules can make themmore resistant to nuclease digestion. The inventors used an in vitrostability assay and purified RNase A (Ambion, cat. no. AM2270) tocompare the stabilities of the modified and unmodified miR-124 mimics.

miR-124 mimics were prepared by hybridizing complementaryoligonucleotides having 2′O-Me-modified nucleotides at various positionsand incubating the hybrids with 720 U of RNaseA at 37° C. for 30 min.Following the 30 min incubation dithiothreitol (DTT) was added to afinal concentration of 10 mM and the mixture was heated at 60°πC. for 10min to inactivate RNase activity. RNA was reverse transcribed withMMLV-RT (Invitrogen, cat. no. 28025-021) using the hsa-miR-124 TaqMan®MicroRNA assay RT primer (Applied Biosystems Inc.; cat. no. 4427975,assay ID 000446). qRT-PCR was performed on the cDNA using the TaqMan®MicroRNA assay with a primer specific for hsa-miR-124 and Platinum TaqPolymerase (Invitrogen, cat. no. 10966-083), in a 7900HT Fast Real-TimePCR System (Applied Biosystems). Table 4 shows the effects of nucleotidemodifications on the stability of various miR-124 mimics.

Table 4. Effects of strand modifications on the stability ofdouble-stranded miR-124 mimics following incubation with RNase A.Passenger and active strand sequences are shown. Bold and italicizedunderlined letters indicate 2′O-Me-modified nucleotides. The active andpassenger strands within each row were hybridized and incubated in anRNase A solution. The relative percentages of double-stranded mimicsremaining after RNase A treatment were calculated by determining thepercentage of double-stranded mimics remaining and dividing by thepercentage of the unmodified double stranded mimic remaining. Valuesgreater than 1.00 indicate modified mimics having more stability thanthe unmodified mimic. A value of 100 in the table would indicate that amodified miR-124 mimic was 100 times more stable than the unmodifiedmiR-124 mimic. A-ID, active strand ID number; P-ID, passenger strand IDnumber. All passenger strands had a 5′-amino C6 modification.

Relative amount of ds Passenger miR-124 mimic after P-ID (SEQ ID NO:4)Active(SEQ ID NO:2) A-ID RNase treatment 101 UGGCAUUCACCGCGU GCCUUAA

KK22 1.29 102

KK22 1.54 107

KK22 2.02 108

KK22 1.04 101 UGGCAUUCACCGCGU UUAAGGCACGCGGUGA 111 1.00 GCCUUAA AUGCCA102

UUAAGGCACGCGGUGA AUGCCA 111 9.74 107

UUAAGGCACGCGGUGA AUGCCA 111 21.45 108

UUAAGGCACGCGGUGA AUGCCA 111 9.12 101 UGGCAUUCACCGCGU GCCUUAA

113 8.26 102

113 9.53 107

113 4.74 108

113 36.90 101 UGGCAUUCACCGCGU GCCUUAA

117 35.73 102

117 22.00 107

117 24.12 108

117 12.58 101 UGGCAUUCACCGCGU GCCUUAA

119 35.32 102

119 129.42 107

119 112.79 108

119 48.06 101 UGGCAUUCACCGCGU GCCUUAA

120 11.03 102

120 3.11 107

120 16.52 108

120 30.30

The mimic having active and passenger strand combination A119/P102 isover 125 times more stable than the unmodified mimic. Heightenedstability of mimics can profoundly improve pharmacodynamic propertiesduring therapy with miRNAs.

In the absence of these data, one might predict that the mimic with themost 2′O-Me-modified nucleotides would be the most stable, because ithas the lowest number of nuclease-sensitive sites. Surprisingly, in ourassay, the most modified mimic (A120/P108) was not observed to be themost stable mimic. These data suggest that simply counting the number of2′O-Me modifications is not an accurate reflection of or a predictableway for determining stability of modified double-stranded miR-124mimics.

Example 4 Nucleotide Modifications in Both Active and PassengenerStrands Contribute to Activity of miRNA Mimics

The anti-proliferative activities of three of the mostnuclease-resistant miR-124 mimics were evaluated and compared to themiR-124 mimic with no 2′O-Me modifications. Lung cancer cells (H460)were reverse transfected with the four different double stranded miR-124mimics and a negative control miRNA (Ambion, cat. no. AM17103) at finalconcentrations of 1, 3, and 10 nM. Lipofectamine 2000 (Invitrogen) wasused according to the manufacturer's recommendations using the followingparameters: 5,000 cells per well in a 96 well plate, 0.1-0.2 μl ofLipofectamine 2000 (cell line specific optimized), in 100 μl totalvolume of media. An alamarBlue® assay (Invitrogen, cat. no. DAL1100) wasperformed on the cells at 3 days post-transfection, according to themanufacturer's protocol. A fluorescent plate reader was used to measureaccumulation of resorufin (560 nm excitation, 590 nm emission) which isthe reduced substrate in alamarBlue®. Resorufin fluorescence correlateswith the number of viable cells per well. The relative percentage ofviable cells for each transfected cell population was calculated bydividing the fluorescence from cells transfected with a givenconcentration of the miR-124 mimic by the fluorescence from cellstransfected with the same concentration of the negative control miRNAand multiplying the result by 100. Values less than 100% indicate thatthe miR-124 mimic reduced the number of viable cells in the populationrelative to cell populations that were transfected with the negativecontrol miRNA. The results are shown in Table 5.

Table 5. Effects of 2′-O Me modifications on the anti-cell proliferationactivity of miR-124 mimics following transfection of H460 lung cancercells. Passenger and active strand sequences are shown. Bold anditalicized and underlined letters indicate 2′O-Me-modified nucleotides.The active and passenger strands within each row were hybridized andtransfected into H460 cells at the concentrations shown. A-ID, activestrand ID number; P-ID, passenger strand ID number. Percentage viablecells is the percentage of cells that remain viable followingtransfection with the miR-124 mimic. Values for the negative controlmiRNA were set a 100%. All passenger strands had a 5′-amino C6modification.

Percentage Viable Cells P-ID Passenger Strand Active Strand A-ID 1 nM3 nM 10 nM 101 UGGCAUUCACCGCGUGCCUUAA UUAAGGCACGCGGUGAAUGCCA 111 72% 47%41% 102

CAUUCACCGCGUGCCU

UUAAGG

GUGAAUGCCA 119 49% 36% 29% 107

AUUCACCGCGUGCCU

UUAAGG

GUGAAUGCCA 119 48% 35% 28% 108

UCACCGCGUGCCU

UUAAGG

CGCGGUGA

GCCA 113 59% 38% 29%

Mimic pairs P102/A119, P107/A119, and P108/A113 each demonstratedenhanced nuclease-stability (Table 4) and also exhibited increasedanti-proliferative activity (Table 5). The modified mir124 mimics havesimilar anti-proliferative activities as the standard miR-124 mimiceffect when used at one-third the dose, indicating that the chosenmodified miR-124a mimics are approximately three times more active thanthe standard miR-124 mimic. The three modified mimics have considerablyimproved anti-cell proliferation activities (Table 5) and nucleasestabilities (Table 4) than those observed for the non 2′-O Me-modifiedmimic.

Example 5 Gene Regulation by Modified miR-124 Mimics

miRNAs function as guide sequences for the RNA-Induced Silencing Complex(RISC) regulation of mRNA transcription. After entering the RISC, amiRNA mimic can alter the mRNA transcription profiles of transfectedcells by: (1) inducing RISC to cleave an mRNA that is bound to themiRNA, (2) altering the half-life of a bound mRNA by preventing it frominteracting with ribosomes, and/or (3) causing changes in amounts ofmRNAs that are regulated by genes that themselves are regulated by themiRNA mimic.

To address whether the modified miR-124 mimics have the same effects onmRNA expression that an unmodified miR-124 mimic has, we used mRNAarrays to profile gene transcription in H460 lung cancer cellstransfected with one of two different negative control miRNAs (Ambion,cat. no. AM17111; Ambion, cat. no. AM17103), an unmodified miR-124mimic, or three different modified miR-124 mimics (P102/A119, P107/A119,and P108/A113). miRNA mimics at 1 nm, 3 nM, or 10 nM were complexed with0.2 μl of Lipofectamine 2000 and added to H460 cells at 5,000 per wellin a 96 well plate, in 100 μl total volume of RPMI media. Cells wereharvested at 3 days post transfection, and total RNA was extracted usingthe mirVana™ PARIS™ Kit (Ambion, cat. no. AM1556) following themanufacturer's recommended protocol.

mRNA array analyses were performed by Asuragen, Inc. (Austin, Tex.,USA), according to the company's standard operating procedures. Usingthe MessageAmp™ 11-96 aRNA Amplification Kit (Ambion, cat. no. 1819),200 ng of input total RNA was labeled with biotin. cRNA yields werequantified using an Agilent 2100 Bioanalyzer capillary electrophoresisinstrument (Agilent Technologies, Inc.). Labeled target was hybridizedto Affymetrix mRNA arrays (Human HG-U133A 2.0 arrays) using themanufacturer's recommendations and the following parameters.Hybridizations were carried out at 45° C. for 16 hr in an AffymetrixModel 640 hybridization oven. Arrays were washed and stained on anAffymetrix FS450 Fluidics station, running the wash scriptMidi_euk2v3_(—)450. The arrays were scanned on an Affymetrix GeneChipScanner 3000. Summaries of the image signal data, group mean values,p-values with significance flags, log ratios and gene annotations forevery gene on the array were generated using the Affymetrix StatisticalAlgorithm MAS 5.0 (GCOS v1.3). Data were reported containing theAffymetrix data and result files (cabinet file) and containing theprimary image and processed cell intensities of the arrays (.cel).

The mRNA array profiles for the various samples were compared todetermine their similarities. Pearson product-moment correlationcoefficients between the samples (complete probe set) were calculatedand are shown in Tables 6, 7, and 8. Correlation coefficients for allsamples were observed to be greater than 0.98.

TABLE 6 Pearson product-moment correlation coefficients following arrayanalysis of gene expression after transfection of lung cancer cells with1 nM of the indicated miRNA mimic. P101/A111 P102/A119 P107/A119P108/A113 1.000 0.998 0.996 0.997 P101/A111 1.000 0.997 0.998 P102/A1191.000 0.998 P107/A119 1.000 P108/A113 Sequences and 2′-O Memodifications of the P-passenger and A-active strands are shown in Table5. All passenger strands had a 5′-amino C6 modification.

TABLE 7 Pearson product-moment correlation coefficients following arrayanalysis of gene expression after transfection of lung cancer cells with3 nM of the indicated miRNA mimic. P101/A111 P102/A119 P107/A119P108/A113 1.000 0.995 0.991 0.988 P101/A111 1.000 0.996 0.995 P102/A1191.000 0.996 P107/A119 1.000 P108/A113 Sequences and 2′-O Memodifications of the P-passenger and A-active strands are shown in Table5.. All passenger strands had a 5′-amino C6 modification.

TABLE 8 Pearson product-moment correlation coefficients following arrayanalysis of gene expression after transfection of lung cancer cells with10 nM of the indicated miRNA mimic. P101/A111 P102/A119 P107/A119P108/A113 1.000 0.987 0.985 0.980 P101/A111 1.000 0.992 0.990 P102/A1191.000 0.997 P107/A119 1.000 P108/A113 Sequences and 2′-O Memodifications of the P-passenger and A-active strands are shown in Table5. All passenger strands had a 5′-amino C6 modification.

Limiting analysis to those mRNAs whose expression levels were altered atleast two-fold by any of the miR-124 mimics used, the strongestcorrelations were observed between cells transfected with 3 nM of the2′-O Me modified miR-124 mimics and 10 nM of the unmodified miR-124mimic (Table 9). This is unsurprising given the approximately three-foldgreater activities for the 2′-O Me-modified miR-124 mimics than themiR-124 mimic with no 2′-O Me modifications that we observed in Example4. These data reveal that the target specificities of the three modifiedmiR-124 mimics are the same as the unmodified miR-124 mimic.

TABLE 9 Pearson product-moment correlation coefficients following arrayanalysis of gene expression altered at least two-fold after transfectionof lung cancer cells with 10 nM of the miR-124 mimic having no modifiednucleotides (P101/A111) and 3 nM of other miR-124 mimics (P102/A119,P107/A119, P108/A113). P101/A111 P102/A119 P107/A119 P108/A113 1.0000.949 0.939 0.944 P101/A111 1.000 0.981 0.968 P102/A119 1.000 0.979P107/A119 1.000 P108/A113 Sequences and 2′-O Me modifications of theP-passenger and A-active strands are shown in Table 5.. All passengerstrands had a 5′-amino C6 modification.

In addition to global expression profiles, we compared the activity of2′O-Me-modified and unmodified miR-124 mimics on known miR-124 targetgenes. Array data revealed that levels of two direct mRNA targets ofmiR-124, VAMP3 and ATP6VOE1, were significantly reduced in all of themiR-124-treated cell populations when compared to cells transfected witha negative control miRNA (Table 10).

TABLE 10 VAMP3 or ATP6VOE1 mRNA levels following transfection of H460cells with the indicated miR-124 mimic at a concentration of 1 nM, 3 nM,or 10 nM. Percentage Expression vs. Negative Control miRNA VAMP3ATP6VOE1 miR-124 Mimic 1 nM 3 nM 10 nM 1 nM 3 nM 10 nM P101/A111 69.0274.35 33.96 81.16 61.31 44.55 P102/A119 72.44 34.75 14.85 76.27 47.6238.36 P107/A119 76.79 43.08 9.30 72.72 43.48 32.18 P108/A113 56.48 28.5411.11 72.30 44.90 30.20 Values represent percentage expression comparedto that observed following transfection of cells with a negative controliniRNA (100%). Sequences and 2′-O Me modifications of the P-passengerand A-active strands are shown in Table 5. All passenger strands had a5′-amino C6 modification.

Example 6 Pharmakokinetic Properties of 2′O—Me-Modified miR-124 Mimics

Improved circulation time and target cell uptake can enhance theeffectiveness of treatment with therapeutic oligonucleotides. Todetermine if the 2′-O Me-modified miR-124 mimics had improvedpharmacokinetic properties relative to the unmodified miR-124 mimic,mice having H460 lung cancer xenografts were repeatedly dosed withmiR-124 mimics and then evaluated for circulating and tissue-associatedlevels of miR-124.

Lung tumor xenografts were induced in NOD/SCID mice by injecting 3×10⁶human lung cancer cells (H460) in 50% matrigel into the flanks of themice (n=7). The mice were checked periodically for firm nodules at theinjection sites to determine the time at which tumors had grown to ˜100mm³. Tumors were detected at day 11, whereupon tail vein injections witheither the unmodified mimic or one of the three 2′-O Me-modified mimicswere initiated at a rate of 20 μg mimic per animal per dose. Doses wererepeated once every two days for two weeks. Animals were sacrificed 10or 60 minutes following the final dose given. Blood, tumors, and liverswere recovered from each animal. RNA was isolated from each of thesamples using the mirVana™ PARIS™ Kit (Ambion, cat no AM1556).

miR-124 levels in blood, tumor, and liver samples were measured byqRT-PCR 10 and 60 minutes after tail vein injections of unmodified(P101/A111) or modified mimics (P102/A119, P107/A119, P108/A113) ofmiR-124. miRNA levels were measured using a TaqMan® MicroRNA Assay(Applied Biosystems; Foster City, Calif., USA). To enable samplenormalization, levels of miR-103, miR-191, and miR-24 were also measuredby qRT-PCR using TaqMan® MicroRNA Assays. Prior to starting the reversetranscription (RT) reaction, 10 ng of total RNA was mixed with 0.5 μl ofRT primer and enough water to bring the total volume to 5 μl. TheRNA/primer mix was heated to 90° C. for 1 minute then transferred to 4°C. Water (2.85 μl), 10× RT buffer (1 μl), 2.5 mM dNTPs (1 μl), RIP (0.1μl of 40 U/μl), and MMLV-RT (0.05 μl of 200 U/μl) were added to eachtube on ice. RT reactions were incubated in a 384-well GeneAmp® PCRSystem 9700 (Applied Biosystems) at 4 C for 30 minutes, then at 16° C.for 30 minutes, then at 42° C. for 30 minutes, then at 85 C for 5minutes.

PCR components (Table 11) were assembled on ice prior to the addition ofcDNA (2 μl) from the RT reaction. Reactions were incubated in an ABIPRISM™ 7900HT Fast Real-Time PCR system (Applied Biosystems) at 95° C.for 1 minute, then for 50 cycles at 95 C for 5 seconds and 60 C for 30seconds. Results were analyzed with the 7900HT Fast Real-Time PCR systemSDS V2.3 software (Applied Biosystems).

TABLE 11 PCR components. μl per Final Component 15 μl rxn ConcentrationNuclease-free water 7.8 MgCl₂ (50 mM) 1.5 5 mM (Invitrogen Corp.;Carlsbad, CA, USA) 10X Platinum PCR Buffer, Minus Mg 1.5 1X (InvitrogenCorp.; Carlsbad, CA, USA) dNTP mix (2.5 mM each) (Ambion, Inc.; 1.5 0.25mM each Austin, TX USA) 20X TaqMan Assay Buffer 0.3 0.4 X  50X ROXPassive Reference 0.3 1X Platinum ® Taq DNA Polymerase 0.1 0.033 U/μl (5U/μl) (Invitrogen) cDNA from RT reaction 2.0 All reaction componentswere as provided by the manufacturer (Applied Biosystems; Foster City,CA, USA) unless otherwise specified.

The qRT-PCR data from miR-103, miR-191, and miR-24 were initiallyassessed to identify samples with too little miRNA to accuratelymeasure. These samples were not subjected to additional analysis.Samples in which the miR-124 Ct value exceeded 40 were also eliminated.The geometric mean of the miR-24, miR-103, and miR-191 Ct data for eachremaining sample was calculated, and the resulting Ct was subtractedfrom the raw Ct readings for miR-124 in the corresponding sample toproduce a dCt. The resulting normalized values for the samples were usedto estimate the relative abundance of miR-124 in each of the samples.The changes in miR-124 levels in blood, liver, and tumor were calculatedby subtracting the average dCts of samples taken from mice that weretreated with a negative control miRNA (Life Technologies, Inc./Ambion,Inc; Austin, Tex., USA; cat. no. AM17103) from the average dCts ofsamples taken from mice treated with the various miR-124 mimics. Theresulting ddCt values for each miR-124 mimic were used to calculate thefold increase in miR-124 levels in the various tissues by raising 2 tothe power of the ddCt value. The miR-124 fold increases over endogenouslevels observed in the various tissues following injection of each miRNAmimic are shown in Table 12.

TABLE 12 Circulation and tissue accumulation of miR-124 mimics in mice.Time Post Blood Tumor Liver Final mir-124 Fold Fold Fold Injection MimicIncrease SD Increase SD Increase SD 10 min P101/A111 52 5 139 27 18 3 10min P102/A119 347 39 135 53 95 9 10 min P107/A119 1722 119 183 28 154 3010 min P108/A113 1779 61 381 105 245 15 60 min P101/A111 3 1 4 1 3 2 60min P102/A119 40 11 92 47 6 3 60 min P107/A119 73 17 50 26 16 3 60 minP108/A113 118 8 73 5 17 4 Sequences and 2′-O Me modifications of theP-passenger and A-active strands are shown in Table 5. All passengerstrands had a 5′-amino C6 modification.

Ten minutes after injecting mice with miR-124 mimics, the inventorsobserved miR-124 levels in blood that were 52-fold to 1,779-fold higherthan levels observed after injection with a negative control miRNA.Elevated miR-124 levels were also observed in blood sixty minutes afterinjection with mimics. Injection with each of the 2′O-Me-modified mimicsinduced higher comparative blood levels of miR-124 than did injectionwith the unmodified mimic. Similar results were observed for miR-124levels in liver tissues and in the xenograft tumors. The resultsindicate that the 2′O-Me-modified mimics used here result in enhancedblood, tumor, and tissue persistence as compared to an unmodified mimic.

REFERENCES

The following references, to the extent that they provide exemplaryprocedural or other details supplementary to those set forth herein, arespecifically incorporated herein by reference.

-   Bagga et al., Cell, 122(4):553-563, 2005.-   Calin and Croce, Nat Rev Cancer, 6(11):857-866, 2006.-   Esquela-Kerscher and Slack, Nat Rev Cancer, 6(4):259-269, 2006.-   Freireich et al. Cancer Chemother Rep. 50(4):219-244, 1966.-   Griffiths-Jones et al., Nucleic Acids Res., 34:D140-D144, 2006.-   Hu-Lieskovan et al., Cancer Res. 65(19):8984-92, 2005.-   Jeffs et al., Pharma Res. 22(3):362-72, 2005.-   Lau et al., Science, 294(5543):858-862, 2001.-   Lagos-Quintana et al., RNA, 9(2):175-179, 2003.-   Lee and Ambros, Science, 294(5543):862-864, 2001.-   Lim et al., Nature, 433(7027):769-773, 2005.-   Wiemer, Eur J Cancer, 43(10):1529-1544, 2007.

What is claimed is:
 1. A double-stranded, blunt-ended RNA molecule of 22basepairs in length comprising: a) an active strand comprising i) asequence of SEQ ID NO:2 and ii) a modified nucleotide at one or moreinternal positions, wherein there are no more than 10 modifiednucleotides; and, b) a passenger strand that is fully complementary tothe active strand and comprises i) a 5′ end nucleotide modification andii) modified nucleotides at positions 1 (U), 2 (G), 21 (A), and 22 (A)relative to SEQ ID NO:4.
 2. The RNA molecule of claim 1, wherein theactive strand comprises the sequence of SEQ ID NO:2.
 3. The RNA moleculeof claim 1, wherein the active strand does not have a modifiednucleotide in the first two positions at either end.
 4. The RNA moleculeof claim 1, wherein the modified nucleotides in the active strand areselected from the group consisting of nucleotides located at positions 5(G), 6 (G), 7 (C), 8 (A), 11 (C), 12 (G), 17 (A), and 18 (U) relative toSEQ ID NO:2.
 5. The RNA molecule of claim 4, wherein the active strandcomprises at least two modified nucleotides selected from the group. 6.The RNA molecule of claim 5, wherein the active strand comprises atleast three modified nucleotides selected from the group.
 7. The RNAmolecule of claim 1, wherein the passenger strand comprises a modifiednucleotide located at position 3 (G), 4 (C), 5 (A), 6 (U), 13 (C), 14(G), 15 (U), 16 (G), 17 (C), 18 (C), 19 (U), or 20 (U), relative to SEQID NO:4.
 8. The RNA molecule of claim 1, wherein the passenger stranddoes not have a modified nucleotide located at position 7 (U), 8 (C), 9(A), 10 (C), 11 (C), or 12 (G) relative to SEQ ID NO:4.
 9. The RNAmolecule of claim 1, wherein the passenger strand has at least sixmodified nucleotides in the passenger strand.
 10. The RNA molecule ofclaim 1, wherein the 5′ end modification of the passenger strandcomprises a lower alkylamine group.
 11. The RNA molecule of claim 1,wherein the modified nucleotides are modified with a sugar modification.12. The RNA molecule of claim 11, wherein the sugar modification is2′-OMe.
 13. A double-stranded, blunt-ended RNA molecule of 22 basepairsin length comprising: a) an active strand comprising: i) a sequence ofSEQ ID NO:2 and ii) a modified nucleotide at one or more internalpositions, wherein the strand does not have a modified nucleotide at its5′ end and there are no more than 10 modified nucleotides; and b) aseparate passenger strand that is fully complementary to the activestrand that comprises: i) the passenger strand comprising the sequenceof nucleotides 2 through 21 of SEQ ID NO:4, ii) a 5′ end nucleotidemodification and at least one more modified nucleotide, iii) modifiednucleotides at positions 1 (U), 2 (G), 21 (A), and 22 (A) relative toSEQ ID NO:4, and iv) wherein the nucleotides located at positions 7-19with respect to the sequence of SEQ ID NO:4 are not modified.
 14. Apharmaceutical composition comprising the RNA molecule of claim
 1. 15. Amethod for providing miR-124 activity to a cell comprising administeringto the RNA molecule of claim
 1. 16. A double-stranded, blunt-ended RNAmolecule of 22 basepairs in length comprising: a) an active strandcomprising i) a sequence of SEQ ID NO:2 and ii) no more than 10 modifiednucleotides; and, b) a passenger strand that is fully complementary tothe active strand and comprises i) a 5′ end nucleotide modification andii) modified nucleotides at positions 1 (U), 2 (G), 21 (A), and 22 (A)relative to SEQ ID NO:4.
 17. The RNA molecule of claim 16, wherein thepassenger strand further comprises a modified nucleotide located atpositions 3 (G) and/or 20 (U) relative to SEQ ID NO:4.
 18. The RNAmolecule of claim 1, wherein the passenger strand further comprises amodified nucleotide located at positions 3 (G) and/or 20 (U) relative toSEQ ID NO:4.
 19. The RNA molecule of claim 13, wherein the passengerstrand further comprises a modified nucleotide located at positions 3(G) and/or 20 (U) relative to SEQ ID NO:4.
 20. The RNA molecule of claim1, wherein the passenger strand further comprises at least one moremodified nucleotide in the first six nucleotides and/or the last sixnucleotides with respect to the 5′ end of the passenger strand.